I tried to go to one of my local websites and encountered this error in the event log: "The worker process for application pool 'My Website' encountered an error 'Cannot read configuration file ' trying to read configuration data from file '\\?\', line number '0'. The data field contains the error code."
I received a 503 Service Unavailable on the website and the app pool is stopped.
The solution was to go to C:\inetpub\temp\appPools. In my case, there was a shortcut with the name of my website that doesn't go anywhere. I deleted the shortcut and restarted the website. A folder with the name of the website is created with a .config file inside of it. After that, the website works and the app pool continues running.
This was a strange error. I hope this will help anyone else who encounters it.