User received error while accessing a foundation site or forms site as "HTTP 500 Internal Server"
The 500 Internal Server Error is a very general HTTP status code that means something has gone wrong on the website's server, but the server could not be more specific on what the exact problem is. The 500 Internal Server Error message might be seen in any number of ways because each website is allowed to customise the message.
One of the solution is to make sure the web application on which the sites are configured is started and running as expected in Internet Information Services (IIS).
Known Causes of 500 Errors
- A 500 can be generated if the SecurityTokenService used for WCF web services is not starting correctly. This component is installed as part of a SharePoint farm and is required for SharePoint and Winshuttle components to function.
- Ensure the SecurityTokenService is responding to token requests by checking SharePoint ULS logs on the same server for token request failures.
- Ensure the SecurityTokenService application pool is started.
Note:- Please check if all application pools are in running state. Check event viewer logs on SP server having winshuttle sites for any critical error. Check relevant component logs like workflow logs for workflow site.