MVC – The dreaded "Multiple types were found that match the controller named"

 

So I have spent time on a project involving MVC and have this dreaded issue that many users seem to have with the routing once you change any of the defaults (for instance areas and namespaces). The error is "Multiple types were found that match the controller named"

After a lot of banging my head against the wall, crying and almost throwing my laptop out the window, i came across a web site by <a href ="http://www.johnplummer.com/code/mvc-multiple-types-were-found-that-match-the-controller-named-home.html/comment-page-1#comment-33365">John Plummer</a> which mentioned that VS likes to keep your original executable
from when you first created the project and instead of renaming the executable, it just creates another one. This is one of the usual major issues that this error can created.

Another issue that can cause this is the changing of namespaces and adding areas. If you add the new string to the end of your area registration page like below, it will route your area’s to the correct controllers:

new { action = "Index", id = UrlParameter.Optional }, new string[] { "CISE.UserInterface.Controllers"}

Hope this helps others!!