Add controller error unable to retrieve metadata

Question

I want to add controller in my MVC 4 application in VS2012 as this image:

Model:

Answer 1

My post may help in case someone has the same problem.

I tried experimenting with EF6 and EF5 in the same project, and I noticed that the tag was messed up, and got the same problem above.

Here is what I did, and it solved the problem:

1. I removed the tag from Web.config
2. Uninstalled entity framework from my MVC app using nuget
3. Installed entity framework to my MVC app again

After removing the tag and re-installing EF5 it was fixed, and I can scaffold my controllers again.