How can I resolve this error: Loading the include file 'EF.Utility.CS.ttinclude' returned a null or empty string

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.

In VS 2012, the EF.Utility.CS.ttinclude file will only be installed if the Microsoft Web Developer Tools or Microsoft SQL Server Data Tools component is selected.

Reinstalling Entity Framework 6 Tools for Visual Studio 2012 http://www.microsoft.com/en-us/download/confirmation.aspx?id=40762 work for me