Entity Framework code first migrations throwing error

Question

Here is what I did before I got this error:

1. Installed EF (the pre release version, 6 maybe, I dunno)
2. decided I did not want, so uninstalled that and reins

Answer 1

I have Windows 10. The following steps corrected the issue

1. Open Program and Features and do a search for 'entity'
2. I noticed an update was installed on 1/23/2016 after the 6.1.3 update on 7/22/2015
3. Selected the 'Entity Framework 6.1.3' etc.. update
4. Clicked on the "Repair" button. After the repair completed I restarted Visual Studio and issue no longer surfaced.

Thanks to @Farshid for the initial clue to a resolution.