Last post Aug 26, 2013 03:04 AM by Angie xu - MSFT
Aug 23, 2013 03:07 PM|dlchase89|LINK
Aug 24, 2013 06:25 AM|Kulrom|LINK
Somewhere in your web.config hierarchy (application level, site level etc) there is a <compiler>/<compiler> tag pointing to .NET 3.5 which is confusing the web server.
Use Ctrl+F and search the entire project for "3.5" ... then when it's found modify to 4.0 and it will work as expected.
Also you may want to check out the following posts:
Aug 24, 2013 08:54 AM|dlchase89|LINK
Aug 26, 2013 03:04 AM|Angie xu - MSFT|LINK
Any application fails with an HTTP Error 503. The service is unavailable.
For this error message, the request is sent to an application pool that is currently stopped or that is currently disabled. To resolve this issue, make sure that the destination application pool is started. The event log may give information about why the
application pool is stopped or disabled.