SharePoint Designer: 500 - Internal Server Error

Question

I got The page cannot be displayed because an internal server error has occurred 500 - Internal Server in SharePoint Designer 2013 when editing Master Page and Page Layout in SharePoint Designer. However, I can edit other pages without any issue with the same account.

SharePoint Designer The server could not complete your request

SharePoint Designer: 500 - Internal Server Error

IIS 8.0 Detailed Error - 500.0 - Internal Server Error

HTTP Error 500.0 - Internal Server Error The page cannot be displayed because an internal server error has occurred. Most likely causes:
  
IIS received the request; however, an internal error occurred during the processing of the request. The root cause of this error depends on which module handles the request and what was happening in the worker process when this error occurred. 
- IIS was not able to access the web.config file for the Web site or application. This can occur if the NTFS permissions are set incorrectly. 
- IIS was not able to process configuration for the Web site or application. 
- The authenticated user does not have permission to use this DLL. 
- The request is mapped to a managed handler but the .NET Extensibility Feature is not installed.     

Things you can try:

- Ensure that the NTFS permissions for the web.config file are correct and allow access to the Web server's machine account. 
- Check the event logs to see if any additional information was logged. 
- Verify the permissions for the DLL. Install the .NET Extensibility feature if the request is mapped to a managed handler.
- Create a tracing rule to track failed requests for this HTTP status code. 
For more information about creating a tracing rule for failed requests, click here.

Detailed Error Information:

Module   ManagedPipelineHandler Notification   ExecuteRequestHandler Handler   ScriptHandlerFactory Error Code   0x00000000     Requested URL   http://servername/_vti_bin/webpartpages.asmx Physical Path   C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\15\isapi\webpartpages.asmx Logon Method   Federation Logon User   0#.w|sp\testuser

More Information: 

This error means that there was a problem while processing the request. The request was received by the Web server, but during processing a fatal error occurred, causing the 500 error. View more information » Microsoft Knowledge Base Articles: 294807     

I also tried to browse this URL in http://servername/_vti_bin/webpartpages.asmx in the browser and it's working properly!!

Why did I get this error 500 internal error in SharePoint Designer 2013, and How to fix it?

Answer 1

Solving 500 internal error in SharePoint Designer 2013

In SharePoint Designer 2013, the main root cause of this issue "The page cannot be displayed because an internal server error has occurred" is there are duplicate entries in the web.config of your SharePoint web application.

Unfortunately, the duplicate entries in the SharePoint web application web.config may not show an error when browsing the website. So I would suggest If you have a web.config backup for your SharePoint web application before facing this issue, try to restore it to make sure that the issue is mainly related to the new changes that you have performed on the current web config file.

How to fix "The page cannot be displayed because an internal server error has occurred" in SharePoint Designer 2013?

To solve the 500 internal error in SharePoint Designer 2013, you have to follow the below steps

Steps:

1. Open IIS.
2. Expand Sites > and right-click on the site that you are facing this issue > then select Explore.
   

   Note: Don't forget to take a backup from the Web.Config file before performing any kind of changes to allow a rollback.

3. Replace the last backup you have taken before facing this issue.
4. Perform IIS reset.
   
5. Check if you can now able to edit Master Page and Page Layout in SharePoint Designer without facing "The page cannot be displayed because an internal server error has occurred"
6. If the latest web.config backup doesn't help, so you have to edit the web config file and trace your latest changes and try to check and remove any duplicate entries.

It's also recommended to read 500 Internal Server Error SharePoint 2013

Comments

Thank you Mohamed, your guidelines helped me alot to solve my issue, the problem was related to web.config file where one entry has been added twice!