Don’t even try using MVC2 on CMS6

...yet. Unfortunately it’s not possible to use ASP.NET MVC 2 on CMS6 (without running into a lot of trouble). The reason is that parts of EPiServer uses MVC1 and there are breaking changes between MVC1 and MVC2 preventing a simple assembly redirect.

The offending changes

The particlar changes that cause problems in this case are these:

• Http GET and return Json needs to be explicitly allowed in code return Json(…, JsonRequestBehavior.AllowGet);
• Change of return type to MvcHtmlString on html helpers
• Async controllers feature introduces a new way of calling the controller factory

Future upgrades of ASP.MVC

Now, if you’re using MVC1 please be aware that we’re planning to update ASP.NET MVC to version 2 and that you might be affected by changes above, or any of the other changes described in the ASP.NET MVC 2 RTM release notes 

I’ve heard several requests to use MVC the second. If you feel this upgrade might be a problem don’t hesitate to add your comment below.