Error: «Could not load type MvcApplication»

As dumb as it might sound, tried everything and it did not work and finally restarted VS2012 to see it working again.

-For me, the fix was to change the output path in the build tab. I changed the output path to bin\ and the error went away.

-Another fix could be that you have the wrong start up project set.

I was getting the same error and inspite of doing everything mentioned here and elsewhere nothing worked. Turned out that I had copied the source code of global.asax.cs from a previous version of the project which had a different name. So the namespace Test should have been namespace Test.WebUI. A silly mistake of course and am a bit embarrassed to write this! But writing in the hope that a similar error from anyone else may lead him to check this trivial aspect as well.

Just do a manual build on your solution.

If you are using local IIS try deleting the website registration in IIS manager and then recreating it manually.