29. May 2011 08:28
Receiving a service unavailable response on a website usually indicates the Application pool of the site is not running.
To solve this, open your InternetInformation Management and verify all required app pools are started.
The page content would look like this:
HTTP Error 503. The service is unavailable.
Embedded in CRM the error would look like
Issue can be caused by problems during upgrading as upgrading stops the app pool to avoid files in use issues.