A route named “x” is already in the route collection. Route names must be unique. Exception with ASP.NET MVC 3

Question

I\'m doing an ASP.NET MVC 3 web service and I keep getting this exception intermittently.

Stack trace:

Server Error in \'/\' Application.

A route n         


        

Answer 1

I found out that Global.asax was referring to an old version of the site's DLL file before I renamed it. The DLL was not being cleaned up when I did Build > Clean up because the VS project/solution didn't refer to it any more. It seems that sometimes only the newer version of the DLL was being used, allowing the site to work correctly, but eventually both of them would be loaded causing the route conflicts.