After installing the Fall Creators Update on Windows 10, IIS promptly stopped working.
In the event viewer, the following vague message appeared on various app pools:
The worker process for application pool 'DefaultAppPool' encountered an error 'Cannot read configuration file
' trying to read configuration data from file '\\?\', line number '0'. The data field contains the error code.
Ajeet Yelandur had a solution, and it works well:
Stop “Windows Process Activation Service” and “W3SVC” service and clean out (delete) all the files under C:\Inetpub\temp\AppPools*. Start your services and the sites should be back to work.
Thank you Ajeet!
(Posted here to help other searchers. It took me a while to find the solution amongst increasingly noisy Google results.)