After updating Local Install get a Error xxx is not a valid 32bit Application
During an update from 5.6.2 to 4.2.3 I encountered an error on starting the website that vslangproj80.dll was not a valid 32bit application.
Mike gave me the solution it is to go to IIS and make this change
IIS -> Application Pools -> Select App Pool for the site -> Advanced Settings -> Enable 32 bit apps set it true
Stop and restart the App Pool and website and it will be fixed.