The controller for path '/Login/Index' was not found or does not implement IController

Question

I have a problems used mvc 3 and my application register Area but no functionally when application start get me:

{System.Web.HttpException (0x80004005): The controller for path '/Login/Index' was not 
found or does not implement IController.
   at System.Web.Mvc.DefaultControllerFactory.GetControllerInstance(RequestContext requestContext, Type controllerType)
   at System.Web.Mvc.DefaultControllerFactory.CreateController(RequestContext requestContext, String controllerName)
   at System.Web.Mvc.MvcHandler.ProcessRequestInit(HttpContextBase httpContext, IController& controller, IControllerFactory& factory)
   at System.Web.Mvc.MvcHandler.<>c__DisplayClass6.<BeginProcessRequest>b__2()
   at System.Web.Mvc.SecurityUtil.<>c__DisplayClassb`1.<ProcessInApplicationTrust>b__a()
   at System.Web.Mvc.SecurityUtil.<GetCallInAppTrustThunk>b__0(Action f)
   at System.Web.Mvc.SecurityUtil.ProcessInApplicationTrust(Action action)
   at System.Web.Mvc.SecurityUtil.ProcessInApplicationTrust[TResult](Func`1 func)
   at System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContextBase httpContext, AsyncCallback callback, Object state)
   at System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContext httpContext, AsyncCallback callback, Object state)
   at System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.BeginProcessRequest(HttpContext context, AsyncCallback cb, Object extraData)
   at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)}

Answer 1

This error can occur if the Controller class is declared in the wrong namespace for your Area. Make sure the namespace matches the area registration.

Answer 2

This is an old questions but I really couldn't find the right answer anywhere else. This was my solution:

I have a solution with multiple projects. All projects were in MVC3. I installed Visual Studio 2012 in my machine and it seems that some projects were automatically upgraded to MVC4.

I got this problem "The controller for path '/etc/etc' was not found or does not implement IController" because the project that handled that route was pointin to MVC4.

I had to manually update their references to use MVC3. You can also do that by opening the .csproj file with a text editor. Find the reference to MVC3 and remove this line:

<SpecificVersion>False</SpecificVersion>