After migration of your website (from ServerA to ServerB) to a new Webserver when you try to access the website you get “503 Error – Service Unavailable” Error on your website and IIS Management Console shows that application pool of the site is crashed or stopped. Even after you start the application pool of the site it is getting crashed when someone try to access website.
IIS Application Pool Crashed: The Module DLL C:\Windows\system32\inetsrv\rewrite.dll failed to load.
FIX:- HTTP Error 500.24 An ASP.NET setting has been detected that does not apply in Integrated managed pipeline mode.
Sometime when you try to setup a application for your website on IIS7 you get following error when you load your website.
Recently while working I faced an issue where the website (IIS 7) was showing 503-Internal Server Error. Checking Event viewer shown following Events for IIS