Symptoms

The Administration and Monitoring console can not be opened. An HTTP Error 500.0 is present.

Cause

This issue may be related to an inability to access the original file storage.

Resolution

1. Try to run the application pools as an admin instead of NetworkService:
   
2. If the issue is still present then try to remove the connection string value from the web.config and restart the IIS.
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Additional information

HTTP Error 500.0 - Internal Server Error error when you open an IIS Webpage