Visual Studio 2013 IntelliSense stops working for ASP.NET MVC5 Controllers

Question

I am facing a weird problem in my Visual Studio 2013 ASP.NET MVC 5 project. All of a sudden, the IntelliSense in the Controller classes of the MVC 5 project are not working

Answer 1

In my case, restart didn't work.

So I did the following weird steps :

1. Closed the solution
2. Opened another solution
3. Verified that intellisense worked in this other solution.
4. Closed the other solution
5. Finally, reopened the first solution.

And the intellisense worked again.