Run time error 521 open clipboard can t

How to fix the Runtime Code 521 Can’t open Clipboard

Symptoms of Code 521 — Can’t open Clipboard

Runtime errors happen without warning. The error message can come up the screen anytime Windows is run. In fact, the error message or some other dialogue box can come up again and again if not addressed early on.

There may be instances of files deletion or new files appearing. Though this symptom is largely due to virus infection, it can be attributed as a symptom for runtime error, as virus infection is one of the causes for runtime error. User may also experience a sudden drop in internet connection speed, yet again, this is not always the case.

(For illustrative purposes only)

Causes of Can’t open Clipboard — Code 521

During software design, programmers code anticipating the occurrence of errors. However, there are no perfect designs, as errors can be expected even with the best program design. Glitches can happen during runtime if a certain error is not experienced and addressed during design and testing.

Runtime errors are generally caused by incompatible programs running at the same time. It may also occur because of memory problem, a bad graphics driver or virus infection. Whatever the case may be, the problem must be resolved immediately to avoid further problems. Here are ways to remedy the error.

Repair Methods

Runtime errors may be annoying and persistent, but it is not totally hopeless, repairs are available. Here are ways to do it.

If a repair method works for you, please click the upvote button to the left of the answer, this will let other users know which repair method is currently working the best.

Please note: Neither ErrorVault.com nor it’s writers claim responsibility for the results of the actions taken from employing any of the repair methods listed on this page — you complete these steps at your own risk.

How to fix the Runtime Code 521 Can’t open Clipboard

This article features error number Code 521, commonly known as Can’t open Clipboard described as The Clipboard has already been opened by another application.

Error Information

Error name: Can’t open Clipboard
Error number: Code 521
Description: The Clipboard has already been opened by another application.
Software: Windows
Developer: Microsoft

This repair tool can fix common computer errors like BSODs, system freezes and crashes. It can replace missing operating system files and DLLs, remove malware and fix the damage caused by it, as well as optimize your PC for maximum performance.

About Runtime Code 521

Runtime Code 521 happens when Windows fails or crashes whilst it’s running, hence its name. It doesn’t necessarily mean that the code was corrupt in some way, but just that it did not work during its run-time. This kind of error will appear as an annoying notification on your screen unless handled and corrected. Here are symptoms, causes and ways to troubleshoot the problem.

Definitions (Beta)

Here we list some definitions for the words contained in your error, in an attempt to help you understand your problem. This is a work in progress, so sometimes we might define the word incorrectly, so feel free to skip this section!

• Clipboard — The clipboard is a software facility that can be used for short-term data storage andor data transfer between documents or applications, via copy and paste operations.

Symptoms of Code 521 — Can’t open Clipboard

Runtime errors happen without warning. The error message can come up the screen anytime Windows is run. In fact, the error message or some other dialogue box can come up again and again if not addressed early on.

There may be instances of files deletion or new files appearing. Though this symptom is largely due to virus infection, it can be attributed as a symptom for runtime error, as virus infection is one of the causes for runtime error. User may also experience a sudden drop in internet connection speed, yet again, this is not always the case.

(Can’t open Clipboard) Repair Tool»/>
(For illustrative purposes only)

Causes of Can’t open Clipboard — Code 521

During software design, programmers code anticipating the occurrence of errors. However, there are no perfect designs, as errors can be expected even with the best program design. Glitches can happen during runtime if a certain error is not experienced and addressed during design and testing.

Runtime errors are generally caused by incompatible programs running at the same time. It may also occur because of memory problem, a bad graphics driver or virus infection. Whatever the case may be, the problem must be resolved immediately to avoid further problems. Here are ways to remedy the error.

Repair Methods

Runtime errors may be annoying and persistent, but it is not totally hopeless, repairs are available. Here are ways to do it.

If a repair method works for you, please click the upvote button to the left of the answer, this will let other users know which repair method is currently working the best.

Источник

How To Fix Runtime Error 521

Basics of Can’t open Clipboard

It is most common Can’t open Clipboard condition known as a runtime error (bug). The Microsoft Corporation developers typically evaluate Windows Operating System with a series of modules to remove bugs to meet industry standards. Tragically, problems like error 521 can be missed, and the software will contain these problems on release.

After the initial release, Windows Operating System users might encounter the message «The Clipboard has already been opened by another application.» while running the program. When this happens, end-users can inform Microsoft Corporation about the presence of Can’t open Clipboard bugs. The developer will then be able to rectify its source code and release an update in the market. If there’s a prompt for a Windows Operating System update, it’s usually a workaround for fixing issues like error 521 and other bugs.

Why Runtime Error 521 Occurs?

The first time you might experience a Windows Operating System runtime error is usually with Can’t open Clipboard at program startup. We are going to review at the key causes of error 521 errors:

Error 521 Crash — error 521 locks up any input and it can make the machine crash. This typically occurs when Windows Operating System cannot recognize that it is given an incorrect input, or is unaware of what it is supposed to produce.

Can’t open Clipboard Memory Leak — Error 521 memory leak results in Windows Operating System increasing in size and horsepower utilized, causing poor systems efficiency. Memory corruption and other potential errors in code may happen when the memory is treated incorrectly.

Error 521 Logic Error — You can experience a logic error when the program produces incorrect results even if the user specifies the right value. This occurs when Microsoft Corporation’s source code triggers vulnerability in information processing.

Can’t open Clipboard issues are often the result of the file that is missing, deleted, or accidentally moved from Windows Operating System’s original installed location. The primary way to resolve these problems manually is to replace the Microsoft Corporation file with a fresh copy. As a supplemental troubleshooting step, we highly recommend cleaning up any invalid file path and Microsoft Corporation file extension references that could contribute to creating these Can’t open Clipboard error messages.

Classic Can’t open Clipboard Problems

Encountered Can’t open Clipboard Problems with Windows Operating System Include:

• «Can’t open Clipboard Software Error.»
• «Can’t open Clipboard not valid.»
• «Can’t open Clipboard has encountered a problem and needs to close. We are sorry for the inconvenience.»
• «Cannot find Can’t open Clipboard.»
• «Can’t open Clipboard can’t be found.»
• «Error starting program: Can’t open Clipboard.»
• «Can’t open Clipboard not working.»
• «Can’t open Clipboard halted.»
• «Faulty Program Path: Can’t open Clipboard.»

Windows Operating System-involved Can’t open Clipboard issues happen during install, when Can’t open Clipboard-related software is running, startup or shutdown, or during the Windows installation process. Keeping track of when and where your Can’t open Clipboard error occurs is a critical piece of information in troubleshooting the problem.

Can’t open Clipboard Problem Causes

Can’t open Clipboard problems can be attributed to corrupt or missing files, invalid registry entries associated with Can’t open Clipboard, or a virus / malware infection.

Especially, Can’t open Clipboard errors stem from:

• Invalid Can’t open Clipboard or corrupted registry key.
• Malware infestation corrupted Can’t open Clipboard file.
• Can’t open Clipboard maliciously, or mistakenly, removed by another software (apart from Windows Operating System).
• Another program is in conflict with Windows Operating System and its shared referenced files.
• Windows Operating System (Can’t open Clipboard) corrupted during download or install.

Compatible with Windows 11, 10, 8, 7, Vista, XP and 2000

Источник

Как исправить время выполнения Ошибка 521 Ошибка Acrobat Reader 521

В этой статье представлена ошибка с номером Ошибка 521, известная как Ошибка Acrobat Reader 521, описанная как Ошибка 521: Возникла ошибка в приложении Adobe Reader. Приложение будет закрыто. Приносим свои извинения за неудобства.

Информация об ошибке

Имя ошибки: Ошибка Acrobat Reader 521
Номер ошибки: Ошибка 521
Описание: Ошибка 521: Возникла ошибка в приложении Adobe Reader. Приложение будет закрыто. Приносим свои извинения за неудобства.
Программное обеспечение: Adobe Reader
Разработчик: Adobe Systems Inc.

Этот инструмент исправления может устранить такие распространенные компьютерные ошибки, как BSODs, зависание системы и сбои. Он может заменить отсутствующие файлы операционной системы и библиотеки DLL, удалить вредоносное ПО и устранить вызванные им повреждения, а также оптимизировать ваш компьютер для максимальной производительности.

О программе Runtime Ошибка 521

Время выполнения Ошибка 521 происходит, когда Adobe Reader дает сбой или падает во время запуска, отсюда и название. Это не обязательно означает, что код был каким-то образом поврежден, просто он не сработал во время выполнения. Такая ошибка появляется на экране в виде раздражающего уведомления, если ее не устранить. Вот симптомы, причины и способы устранения проблемы.

Определения (Бета)

Здесь мы приводим некоторые определения слов, содержащихся в вашей ошибке, в попытке помочь вам понять вашу проблему. Эта работа продолжается, поэтому иногда мы можем неправильно определить слово, так что не стесняйтесь пропустить этот раздел!

• Acrobat — Adobe Acrobat — это семейство приложений, разработанных Adobe для просмотра, создания, обработки, печати и управления файлами в формате Portable Document Format PDF.
• Adobe — Adobe Systems — компания-разработчик программного обеспечения со штаб-квартирой в Сан-Хосе, Калифорния, США.
• Adobe reader — Adobe Reader — бесплатное приложение для просмотра, печать и заполнение PDF-документов.
• Reader — Reader указывает программное обеспечение, которое может читать файлы определенного формата, или аппаратное устройство, которое может читать некоторые карты памяти или подобное устройство.

Симптомы Ошибка 521 — Ошибка Acrobat Reader 521

Ошибки времени выполнения происходят без предупреждения. Сообщение об ошибке может появиться на экране при любом запуске %программы%. Фактически, сообщение об ошибке или другое диалоговое окно может появляться снова и снова, если не принять меры на ранней стадии.

Возможны случаи удаления файлов или появления новых файлов. Хотя этот симптом в основном связан с заражением вирусом, его можно отнести к симптомам ошибки времени выполнения, поскольку заражение вирусом является одной из причин ошибки времени выполнения. Пользователь также может столкнуться с внезапным падением скорости интернет-соединения, но, опять же, это не всегда так.

(Ошибка Acrobat Reader 521) Repair Tool»/>
(Только для примера)

Причины Ошибка Acrobat Reader 521 — Ошибка 521

При разработке программного обеспечения программисты составляют код, предвидя возникновение ошибок. Однако идеальных проектов не бывает, поскольку ошибки можно ожидать даже при самом лучшем дизайне программы. Глюки могут произойти во время выполнения программы, если определенная ошибка не была обнаружена и устранена во время проектирования и тестирования.

Ошибки во время выполнения обычно вызваны несовместимостью программ, запущенных в одно и то же время. Они также могут возникать из-за проблем с памятью, плохого графического драйвера или заражения вирусом. Каким бы ни был случай, проблему необходимо решить немедленно, чтобы избежать дальнейших проблем. Ниже приведены способы устранения ошибки.

Методы исправления

Ошибки времени выполнения могут быть раздражающими и постоянными, но это не совсем безнадежно, существует возможность ремонта. Вот способы сделать это.

Если метод ремонта вам подошел, пожалуйста, нажмите кнопку upvote слева от ответа, это позволит другим пользователям узнать, какой метод ремонта на данный момент работает лучше всего.

Источник

Run Time Error 521: Can’t Open Clipboard» When Merging or Printing Letters With Images

Issue : When merging a letter in Orthotrac using the Edit function, or previewing/printing the letter, the following error message is displayed:

Run Time Error 521: Can’t Open Clipboard

Solution : This error message is a Microsoft Windows error message which indicates an issue with the Operating System or Windows user profile. When merging information from Orthotrac into the Word document, it is the Windows clipboard that is used for this process. The issue tends to occur most frequently when merging letters that include images.

Orthotrac Development is aware of this issue and is working on ways to get around this Windows limitation. In the meantime, the following workarounds can be used to correct the issue if it occurs.

Add SlowImageMerge Command to Orthotrac Settings File

***NOTE: Cloud clients who are experiencing issue will need to contact Support to have these steps performed.

1. On the workstation experiencing the issue, go to Start, Run, type «OMS.INI» and press Enter. The OMS.INI settings file is displayed.

2. Locate the section beginning with the text [AWPS].

3. Underneath the [AWPS] line, add a new line which reads:

4. Save and exit the file.

This process will slow down image merging on that workstation only. Letters with images will take longer to merge, but this will generally correct the issue.

If this does not correct the issue:

Change Letters to Use Thumbnailed Versions of Images

1. From the main menu of Orthotrac, select Functions, Word Processing, Letter Setup.

2. Locate the letter that is having issues. Click it to highlight it and click Change Letter.

3. Click «Edit Letter», «Edit Patient» or «Edit Responsible» depending on the type of letter.

(NOTE: If there is more than one Edit button then both versions of the letter will need to be corrected.)

4. The letter will display onscreen. Locate the merge code for each image. Sample merge code is shown below:

5. Change the second number in the set (in the example, the «1» after the «102») to a 2. Thus, after the change, the merge code would read:

Do not change any other numbers in the Imaging merge code, only the second number in the set.

6. Repeat steps 4-5 for all other images in the letter.

7. Save changes and exit the letter.

8. Click OK to close the Letter Setup window and save changes.

9. Post and print the letter again for any patients that require it.

If this does not correct the issue:

Create a Shortcut to Clear the Clipboard

A third possible workaround is to create a shortcut on the desktop running the following command on Windows 7 / Windows 10 systems. It clears the clipboard manually.

1. On the PC experiencing the issue, right-click anywhere on the desktop and choose New, Shortcut.

2. Enter the following command into the Location field:

cmd /c «echo off | clip»

3. Click Next and give the shortcut a name like «Clear Clipboard».

This command should be run before merging any letters.

Источник

	Error Number:	Runtime Error 521
Error Name:	Can’t open Clipboard
Error Description:	The Clipboard has already been opened by another application.
Developer:	Microsoft Corporation
Software:	Windows Operating System
Applies to:	Windows XP, Vista, 7, 8, 10, 11

Basics of Can’t open Clipboard

It is most common Can’t open Clipboard condition known as a runtime error (bug). The Microsoft Corporation developers typically evaluate Windows Operating System with a series of modules to remove bugs to meet industry standards. Tragically, problems like error 521 can be missed, and the software will contain these problems on release.

After the initial release, Windows Operating System users might encounter the message «The Clipboard has already been opened by another application.» while running the program. When this happens, end-users can inform Microsoft Corporation about the presence of Can’t open Clipboard bugs. The developer will then be able to rectify its source code and release an update in the market. If there’s a prompt for a Windows Operating System update, it’s usually a workaround for fixing issues like error 521 and other bugs.

Why Runtime Error 521 Occurs?

The first time you might experience a Windows Operating System runtime error is usually with Can’t open Clipboard at program startup. We are going to review at the key causes of error 521 errors:

Error 521 Crash — error 521 locks up any input and it can make the machine crash. This typically occurs when Windows Operating System cannot recognize that it is given an incorrect input, or is unaware of what it is supposed to produce.

Can’t open Clipboard Memory Leak — Error 521 memory leak results in Windows Operating System increasing in size and horsepower utilized, causing poor systems efficiency. Memory corruption and other potential errors in code may happen when the memory is treated incorrectly.

Error 521 Logic Error — You can experience a logic error when the program produces incorrect results even if the user specifies the right value. This occurs when Microsoft Corporation’s source code triggers vulnerability in information processing.

Can’t open Clipboard issues are often the result of the file that is missing, deleted, or accidentally moved from Windows Operating System’s original installed location. The primary way to resolve these problems manually is to replace the Microsoft Corporation file with a fresh copy. As a supplemental troubleshooting step, we highly recommend cleaning up any invalid file path and Microsoft Corporation file extension references that could contribute to creating these Can’t open Clipboard error messages.

Classic Can’t open Clipboard Problems

Encountered Can’t open Clipboard Problems with Windows Operating System Include:

• «Can’t open Clipboard Software Error.»
• «Can’t open Clipboard not valid.»
• «Can’t open Clipboard has encountered a problem and needs to close. We are sorry for the inconvenience.»
• «Cannot find Can’t open Clipboard.»
• «Can’t open Clipboard can’t be found.»
• «Error starting program: Can’t open Clipboard.»
• «Can’t open Clipboard not working.»
• «Can’t open Clipboard halted.»
• «Faulty Program Path: Can’t open Clipboard.»

Windows Operating System-involved Can’t open Clipboard issues happen during install, when Can’t open Clipboard-related software is running, startup or shutdown, or during the Windows installation process. Keeping track of when and where your Can’t open Clipboard error occurs is a critical piece of information in troubleshooting the problem.

Can’t open Clipboard Problem Causes

Can’t open Clipboard problems can be attributed to corrupt or missing files, invalid registry entries associated with Can’t open Clipboard, or a virus / malware infection.

Especially, Can’t open Clipboard errors stem from:

• Invalid Can’t open Clipboard or corrupted registry key.
• Malware infestation corrupted Can’t open Clipboard file.
• Can’t open Clipboard maliciously, or mistakenly, removed by another software (apart from Windows Operating System).
• Another program is in conflict with Windows Operating System and its shared referenced files.
• Windows Operating System (Can’t open Clipboard) corrupted during download or install.

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Issue: When merging a letter in Orthotrac using the Edit function, or previewing/printing the letter, the following error message is displayed:

Run Time Error 521: Can’t Open Clipboard

Solution: This error message is a Microsoft Windows error message which indicates an issue with the Operating System or Windows user profile. When merging information from Orthotrac into the Word document, it is the Windows clipboard that is used for this process.  The issue tends to occur most frequently when merging letters that include images.

Orthotrac Development is aware of this issue and is working on ways to get around this Windows limitation.  In the meantime, the following workarounds can be used to correct the issue if it occurs.

Add SlowImageMerge Command to Orthotrac Settings File

***NOTE:  Cloud clients who are experiencing issue will need to contact Support to have these steps performed.

1.  On the workstation experiencing the issue, go to Start, Run, type «OMS.INI» and press Enter.  The OMS.INI settings file is displayed.

2.  Locate the section beginning with the text [AWPS].

3.  Underneath the [AWPS] line, add a new line which reads:

SlowImageMerge=True

4.  Save and exit the file.

This process will slow down image merging on that workstation only.  Letters with images will take longer to merge, but this will generally correct the issue.

If this does not correct the issue:

2.  Locate the letter that is having issues.  Click it to highlight it and click Change Letter.

3.  Click «Edit Letter», «Edit Patient» or «Edit Responsible»  depending on the type of letter. 

(NOTE:  If there is more than one Edit button then both versions of the letter will need to be corrected.)

6.  Repeat steps 4-5 for all other images in the letter.

7.  Save changes and exit the letter.

8. Click OK to close the Letter Setup window and save changes.

9. Post and print the letter again for any patients that require it.

If this does not correct the issue:

Create a Shortcut to Clear the Clipboard

A third possible workaround is to create a shortcut on the desktop running the following command on Windows 7 / Windows 10 systems.  It clears the clipboard manually.

1.  On the PC experiencing the issue, right-click anywhere on the desktop and choose New, Shortcut.

2.  Enter the following command into the Location field:  

cmd /c «echo off | clip»  

3.  Click Next and give the shortcut a name like «Clear Clipboard». 

This command should be run before merging any letters. 

Добрый день!

Пишу программу, которая объединяет документы Word в единый файл, предварительно их обработав.

Алгоритм программы
1) Открываем документ Word, циклом проходим по абзацам, удаляя все абзацы, которые не удовлетворяют условию.
2) Выделяем все содержимое с первого по последний абзац и копируем его.
3) Закрываем документ с сохранением изменений.
4) Открываем итоговый документ и вставляем в него скопированный текст.
5) Закрываем документ с сохранением изменений.
6) Действия с 1 по 5 выполняем для всех документов Word находящихся в папке.

Программа в Windows 7 работает нормально. При работе в Windows 10 возникает ошибка run time error 521 can’t open clipboard.
При чем ошибка возникает не сразу, приложение обрабатывает определенное количество документов и после этого возникает ошибка.

Код программы

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Function proba007(PathName As String)
 
        Dim WordApp As Word.Application ' экземпляр приложения
        Dim WordApp1 As Word.Application ' экземпляр приложения
        Dim DocWord As Word.Document ' экземпляр документа
        Dim DocWord1 As Word.Document ' экземпляр документа
        
        Set WordApp = New Word.Application
        Set WordApp1 = New Word.Application
        'определяем видимость Word-a по True - видимый,
        'по False - не видимый (работает только ядро)
        WordApp1.Visible = False
        Set DocWord1 = WordApp1.Documents.Open(PathName) 'Исходный объединяемый файл
        
        DocWord1.Activate ' активируем документ
        'Копируем документ с первого по последний абзац
        DocWord1.Range(DocWord1.Paragraphs(1).Range.Start, DocWord1.Paragraphs(DocWord1.Paragraphs.Count).Range.End).Copy
                   
       DocWord1.Close True 'Закрываем документ с сохранением изменений
       WordApp1.Quit 'закрываем экземпляр приложения
        
        WordApp.Visible = False
        Set DocWord = WordApp.Documents.Open(ItogFilePathCR)  'Исходный итоговый файл
        DocWord.Activate
        
        'Проверяем, что буфер обмен не пуст, и вставляем содержимое буфера в докумен с позиции последнего абзаца документа
        If Len(Clipboard.GetText) <> 0 Then DocWord.Paragraphs(DocWord.Paragraphs.Count).Range.Paste
       Clipboard.Clear 'очищаем содержимое буфера
                    
        DocWord.Close True 'Закрываем документ сохраняя изменения
        WordApp.Quit 'Закрываем приложение Word
 
        
End Function

Error 521 is essentially a Cloudflare-based message that usually occurs when the WordPress website server is unable to establish a connection with Cloudflare.

”Error 521 Web Server is Down” appears for various reasons and very often, it is one of the most difficult errors to resolve

Unlike other codes that are related to quite unique situations, error 521 is indeed related to websites that use CloudFlare. But, at the same time, it doesn’t say much about specific causes and situations. This actually complicates its resolution.

In order to help you get an overview of error 521 and understand how you can solve it, I suggest you read this article carefully

Chapter 1: What causes Error 521 and how to recognize it?

In order to provide you with a perfect understanding of the concept of Error 521, here are the points that we will develop together in this first chapter:

• Definition of Error 521;
• Definition of Cloudflare ;
• Causes of Error 521 and clues to recognize it.

1.1) What is the 521 error?

Error 521, also known as server not found, is an error particularly related to websites hosted with Cloudflare. It often tends to work like the 504 gateway error, but the difference lies in the problem that caused the error.

As a reminder, it means that Cloudflare’s connection to the origin server on port 80 or 443 was rejected, resulting in users seeing the 521 code.

Source hooshmand

As a result, the user will receive a connection rejection message that may or may not make it clear that it is a 521 code.

1.2 What is Cloudflare?

It is a network that has the role of content delivery and works as a proxy between the visitor’s browser and your website.

Cloudflare is mainly used to improve the performance, speed and security of applications and websites

In addition, Cloudflare secures the website against identity theft or SQL injections as threats.

1.3. Main causes of Cloudflare error 521

There are three main problematic factors that can cause this error in the user’s system while using Cloudflare service. And these factors are explained as follows:

• Web server is offline

The first problem that can cause this error in a Cloudflare user system is an idle origin web server

Sometimes, the original web server process like Apache or Nginx is unable to run or crashes due to a server malfunction. And across the board, these things create the 521 error.

• Blocked Cloudflare requests

The second main thing that can create this error in Cloudflare is the request block issue

In some situations, the origin web server or the hosting provider’s network blocks Cloudflare requests and, as a result, creates connection blocking scenarios

And the 521 error is essentially a way in which Cloudflare informs its users of this problem.

• Poor detection

Due to its proxy nature, Cloudflare accesses your WordPress server with an IP address that is often the same. In fact, the IP address of each visitor should be different.

This is why your server security system may consider it a hacker attack

This is because the server detects the amount of traffic from IP addresses that are similar to each other. As a result, the server will block the Cloudflare IP address and an error code 521 will appear.

1.4. How to recognize the 521 error?

It is not always obvious that this error only occurs during a browsing session or that you receive a message indicating that you are facing a 521 error. It can occur in several ways, including the following:

• It can occur by closing the window of the active programs on your computer;
• It may involve frequent blocking of your computer when running the same program or website;
• There is a 521 error when you receive a ”Can’t open Clipboard” message;
• The expression ”Clipboard has already been opened by another application” can also mean a 521 error.

These 521 error messages are likely symptoms that will let you know the nature of the error if you don’t have a concrete indication.

Chapter 2: How to fix error 521 for WordPress and Cloudfare?

Since the 521 code is mostly related to WordPress sites, in this chapter we will find out some ways to fix Cloudflare error 521 in WordPress.

Here are the tips I’ll suggest:

2.1. Check if the original server of your site is online

So, before further analysis, you should first make sure that the original server on which you are hosting the website is online.

For testing purposes, I recommend using the cURL command on the original IP server. Especially for those of you using Mac or Linux, you can test directly from the terminal

For example curl 103.56.149.29.

If there is a response, it means that there is no problem with the original server you are using.

Using the cURL command is not a possibility when you are in Windows. The possible checking option is the use of tools such as HTTP Header Check

Simply enter http //1.2.3.4where 1.2.3.4 is considered the real IP address of your server.

Source kinsta

You can find your server’s real IP address from the A record setting that points to your domain in the Cloudflare dashboard.

If your server is UP or Online, an HTTP 200 response usually appears, or if you are using a VPS, the response may be 404 Not Found or 403 Forbidden depending on your VPS settings.

Source fixrunner

But basically, this shows that the origin server is online, as it always gives a response.

Now, what you need to pay attention to, if the origin server is down, the information is Host Not Found or Failed to connect.

In case you suspect that your server is complicit in the problem, then you need to contact your hosting company.

2.2. Grant access to Cloudflare IP addresses

If the server is online and the 521 error keeps appearing, it means that you need to grant access or whitelist all Cloudflare IP addresses so that they are not blocked by the server.

To do this, you need to modify the .htaccess. However, all Cloudflare IP addresses must be confirmed as not blocked.

If you are confused or have any doubts about editing the .htaccess file, just contact your hosting company. You can ask for their help to modify it.

2.3. Check and fix the error in the .htaccess file

If you have tried to fix WordPress errors before, you may have noticed that the .htaccess file has a lot to do with errors.

Unlike other errors, we can’t just regenerate the file and fix the errors. Here we also have to do other things to make sure that the file is correct.

The corrupted .htaccess file is not the reason for error 521. So the solution is also different. To fix it, the first step will be to open the .htaccess file:

• You can open the file manager from cPanel.
• Inside, you will see the .htaccess file. Otherwise, you can access the settings from the top menu. Click on the settings, then you can select “Show hidden files”.
• When you click on the Show hidden files option, you will see the .htaccess file option.
• Now open the file. You can click on the code edit button. Then, you will see the file editor.

Source Fixrunner

You will need to make sure that no IP addresses are blocked. You can confirm that the cloudflare IP addresses have ”.com/ips”. Make sure that none of the IP addresses in this list are blocked.

If the .htaccess file blocks any of the IP addresses, you will need to remove the block. Once this is done, you can try reloading the website to see if it works or not. This will surely solve the problem.

2.4. Change HTTP to HTTPS

When you don’t have an SSL certificate, the website will redirect all HTTP requests. Even if you write HTTPS://example.com, it will be redirected to http://example.com. This is because of the protocol.

Now, when you enable SSL, Cloudflare redirects websites to HTTPS. However, if your actual WordPress domain is set to HTTP, the contradiction will arise. Cloudflare will try to redirect the URL to HTTPS while the website will try to redirect the URL to HTTP. As a result, you will see the error.

The easiest way to solve this problem is to change HTTP to HTTPS. To change it, you can go to the WordPress settings

In the general settings, you will see the option to change the URL. Change the URL and reload the page

Now you can try reloading the website again to see if it works. If everything went well, the website will work fine.

If not, make sure you don’t have the redirect plugin that is causing the problem. If you have a redirect plugin installed, it can cause problems. It is recommended to disable it to see if the plugin is the problem or not. If the plugin is the problem, everything will be better after disabling it.

2.5. Change full SSL to flexible SSL

Cloudflare has different options you can use when it comes to the SSL certificate. The two options we will be concerned with are

• Full SSL ;
• Flexible SSL.

Along with these, there are also various other options. However, we will only consider these two to stay in line with our topic

Very often, full SSL is sometimes complicit in this error. So, you can simply convert the SSL certificate to flexible instead of full.

Here are some steps to access this option

• First, you will need to log in to the dashboard;
• Then you can select the crypto option from the menu tabs
• Take a look at the sidebar and you will see the option to select SSL;
• Change the SSL certificate from full to flexible;
• Wait for it to be activated;
• Try loading the website again to see if it worked or not.

Source Fixrunner

Here is a video that shows you step by step how you can do it:

Alternatively, if you have the Cloudflare WordPress plugin installed on your website, you can also change things from there

If you don’t have it installed yet, you can install Cloudflare Flexible SSL from the WordPress plugin directory

2.6. Contact support

If nothing works, you can probably contact support and see what they have to say about it. You still have two options here. You might not know whether you should contact hosting support or you should contact CDN support.

You can contact hosting support first and ask if there is anything wrong with the server. If you are still not satisfied, then you can contact Cloudflare support team.

In most cases, the problem is related to the hosting and not to Cloudflare. Therefore, you need to contact the hosting support first and then if you don’t have a solution, you can contact Cloudflare support to see what is wrong.

You need to perform the above tips first and if nothing works, you can contact the support.

But in the chapter below, we will see some web server repair solutions.

Chapter 3: Troubleshooting broken server problems

Troubleshooting server problems is never an easy task. Whether you have a small home server or a giant with thousands of computers, you need to follow meticulous steps to get it back up and running

Here is a complete overview of the steps you need to follow when troubleshooting.

3.1. Analyze your network infrastructure

You’ll have a better chance of solving network problems if you start by figuring out where everything is connected in the infrastructure.

Source Ezynow

You’ll be able to spot network vulnerabilities by discovering all the applications, processes and computers on the network.

3.2. Study your network

Several tools can help you map the entire network infrastructure. Tools such as IPCONFIG can help find the problem

3.3. The connection is broken

From the network troubleshooting application, find out from the OSI model if all seven layers are working properly. Usually, if the first layer is not working, the whole connection will be broken

Source Sites.google

Check if the network cable is connected. The problem may also be a broken connection when the network cable is disconnected or cut. Also check if the network switch is working properly.

3.4. No IP address

Your server may be down simply because of unknown IP address settings. A null IP address such as 0.0.0.0 or an automatic address starting with 169.254 will usually cause server failure problems

You will need to obtain a valid IP address before you can back up your server

Source Wikipedia

To solve this problem, open the Networking and Sharing Center and select ”Get IP address automatically”

You can also activate a dHCP server (Dynamic Host Configuration Protocol) server to solve the problem.

3.5. No DNS servers

Without configured DNS servers on your network, all communication will only be possible via an IP address. A problem with a downed server in this case can be a line break between the router and the Internet

Source Slideshare

To solve this problem, set the DNS server to a manual configuration and fill in the server IP addresses. You can also configure Google’s public DNS servers to help you ping and track blocked packets.

3.6. No default gateway

Your servers might be down because there is no default gateway IP address. This interrupts communication between the subnet and the local network

Source Infoforal

You will still be able to work as usual on your local servers. However, if you need to access an external network, you will have to configure a gateway IP address manually.

3.7. Misconfigured IP Subnet Mask

A misconfigured subnet mask IP address can hinder communication with the server

Source Sti2d

You can configure this IP subnet mask manually or work with the DHCP server to identify the source if it is misconfigured.

Chapter 4: Other Questions Asked about Error 521

4.1. What is Error 521?

Error 521 “Web Server is Down” is an error directly related to the Cloudflare 521 error message (similar to error 520) that appears whenever your web server cannot connect with Cloudflare

4.2. What is Cloudflare?

Cloudflare is generally used to increase the security and performance of web applications. It improves the overall performance, security, and reduces the load time of any website hosted through Cloudflare.

4.3. Why does error 521 occur?

The 521 Web Server is Down error can be caused for several reasons, specifically in these three cases:

First, the 521 error occurs because the original web server is refusing a connection from Cloudflare. Specifically, Cloudflare tried to connect to your origin server on port 80 or 443 but received a connection error.

Second, your WordPress site’s server may be down (temporarily). Even if everything is configured correctly on your end, the server may be offline. In this case, Cloudflare will not be able to connect and will display Cloudflare error 521.

Third, your website’s server may be working properly, but may be blocking Cloudflare’s connection requests for some reason

4.4 How do I fix the Cloudflare error?

• First of all, make sure that your original web server is responsive;
• Review the error logs of the origin web server to identify web server application failures;
• Ensure that no Cloudflare IP addresses are blocked or rate-limited;
• Provide access to all Cloudflare IP address ranges in your origin web server’s firewall.

4.5. What does downed web server mean?

A server can go down for many reasons. Perhaps a physical machine is losing power, or perhaps the operating system or network card is having a problem

4.6. How do I fix the crashed server?

Here are some practical actions that can help you:

• Analyze your network infrastructure
• Study your network;
• Make sure the connection is not broken;
• Make sure your IP address is not invalid;
• Make sure there is a DNS server;
• Make sure there is a default gateway;
• Make sure that the IP subnet mask is properly configured.

Conclusion

Error 521 is a code specifically related to websites, whose resolution is a bit more complex unlike the other codes.

But in this article, we have taken the time to develop the basic concepts that can be difficult to understand. By following my advice, you will easily avoid or correct the 521 code

If you have any other questions, feel free to put them in the comments below.

Thanks for reading and see you soon!