I'm having this error pop up once I start Visual Studio professional 2013 with update 3. I don't know whats going on and also when I created a web form and try to put items from the toolbox into a table in my code it doesn't let me. the items are dim and can't select them any more. before I would make a table and try to add Labels, textbox, etc and it wasn't a problem.
Visual Studio 2013 Update 4 Tools -> Extensions and Updates Disabled "Release Management for Visual Studio 2013 v2.1".
That worked for me.