I created a new WinForms project and got this error:
The designer could not be shown for this file because none of the classes within it can be designed.
I have not yet added any code to the project. It appears as if all of the necessary assemblies are referenced, but intellisense can't seem to resolve the Form class.
Shutting VS2012 down and starting it back up again solved the issue. Weird.
".45 ACP - because shooting twice is just silly" - JSOP, 2010 ----- You can never have too much ammo - unless you're swimming, or on fire. - JSOP, 2010 ----- "Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass." - Dale Earnhardt, 1997