Currently, when I open Package Manager Console in VS2013 it is unavailable (all controls are in disabled state). I want to preform migrations in EF7. (EntityFramework.Commands packages from EF7 is installed in the project.)
I am not sure, why it is no longer working, since it was working before. Only what I've changed in the meantime (I am aware): I've installed VS2013 u4 and I've updated EF7 Commands package.
Reinstalling the NuGet Package Manager for Visual Studio 2013 extension seems to solve the problem.
I came across a similar issue after a rogue 'Update-DataBase' command ended up running indefinitely.
Clicking stop wouldn't end the command so I closed the 'Package Manager Console' window and tried to re-open it using 'Tools' -> 'NuGet Package Manager' -> 'Package Manager Console' but found it disabled.
Restarting Visual Studio 2013 resolved this particular issue.