AI OnAI Off
You probably are missing some dlls/have the wrong version. I would setup an alloy template site with the same version and check file version on each dll and compare...
Also check modules where you have some dlls below appData:
I have EPiServer.Cms.Shell.UI.dll below
C:\EPiServer\EPi7dot5Test\appdata\Modules\CMS\bin\net40
This is an internal project which used to be functional earlier, Now it is reopened after a long gap and fails to resolve dependancy , Note: This is not an upgraded version, it was built on 7.5 from scracth.
any pointer?