Very frustrating stuff getting error 503 corroborated with the following entry in the event viewer:
The worker process for application pool ‘DefaultAppPool’ encountered an error ‘Cannot read configuration file
‘ trying to read configuration data from file ‘\\?\<EMPTY>’, line number ‘0’. The data field contains the error code.
This happened to me after a Windows 7 system was upgraded to Windows 10 Pro x64, and enabling IIS. The default IIS page on the localhost wouldn’t show up.
Instead the HTTP error 503 would be front page and center.
Solution: bit of hint to resolve it was from the default IIS pool, DefaultAppPool, which wouldn’t -ever- start!
Navigating on the local file system: C:\inetpub\temp\appPools you should find a folder named DefaultAppPool. In my case I had a shortcut! That needs to be corrected, something like this:
- run inetmgr
- locate the default pool (or any other pool that fails to start)
- click on pool’s name from the right pane chose View Applications
- change the pool of the application to something else
- go back to the list of pools and delete the invalid pool
- then recreate DefaultAppPool / invalid pool
- click the pool that the application got changed, the View Applications and assign back the default pool to it
- restart IIS
At this stage the DefaultAppPool foder should appear in the C:\intepub\temp\appPools and the default, or your local website, should load up.
No more pesky error 503!