I tried to run the command \'Enable-Migrations\' in a new project and I got the message:
PM> Enable-Migrations The term \'Enable-Migrations\' is not recog
Check if the project is open in the Solution Explorer window.
This could be the cause of your problem.
First "Install-Package EntityFramework -IncludePrerelease" and then Restarting Visual Studio as a Administrator worked for me together.