How can I resolve these errors:
Reinstalling Entity Framework 6 Tools for Visual Studio 2012 http://www.microsoft.com/en-us/download/confirmation.aspx?id=40762 work for me
I had very similar issue and I tried with VS2012 and VS2013.
After reinstalling Entity Framework 6 Tools for Visual Studio 2012 http://www.microsoft.com/en-us/download/confirmation.aspx?id=40762 every thing went back to normal.