Today while working on an issue I have found out that all of my IIS requests have started to give HTTP 500 error messages, after looking at event logs I have found out error message similar to
The Template Persistent Cache initialization failed for Application Pool 'DefaultApplicationPool' because of the following error: Could not create a Disk Cache Sub-directory for the Application Pool. The data may have additional error codes.
After checking the following folders I have found out that IIS_WPG group was not present.
systemroot\System32\Inetsrv\ASP Compiled Templates
systemroot\IIS Temporary Compressed Files
On COMMON folder IIS_WPG should have 'Read and Execute', 'List folder contents' and 'Read' permissions.
On rest of the two folder IIS_WPG group should have full permissions.
After adding the permissions just restarted IIS and dependable services and all worked well.