There are two scenarios in which you may see the 'Processor named ‘T4VSHost’ could not be found for the directive named ‘CleanupBehavior’' error after installing Visual Studio 2012 Update 1. Inside Visual Studio when code is being generated from an EF model - this isn't supposed to happen and something probably went wrong during install. … Continue reading Processor named ‘T4VSHost’ could not be found for the directive named ‘CleanupBehavior’