Problem
Entity Framework Power Tools provides useful feature of Entity Framework 6 but is not supported on Visual Studio 2015, only 2010, 2013
Possible Cause
The EF Power Tools is integrated with EF Designer on Visual Studio and it will be replaced on EF 7
Solution
Download the customized package here
Turn the visual studio off
Install it by double click OR by using Administrator account
Check the menu by Right Clicking on a project
Happy coding!