How to fix the error 'System.Web.Mvc.Controller' is not defined

I started out this morning working with my ASP.NET MVC project like normal and everything worked. I added a new class and some functions and it still worked. Then, all of a sudden,开发者_StackOverflow社区 while I was working with a javascript file, I started getting these not defined errors on the MVC classes/functions. There are 118 of them in the project and I'm not sure how to fix them.

I've tried restarting Visual Studio and rebooting the computer. I've also tried loading another MVC project to see if the framework might be hosed, and it works fine. I've checked the references and the ASP.NET MVC 1.0 RC2 dll is there.

Has anyone else ran into this problem?

Please help!

I figured it out. I had added a new Master page to the project, but when did so, I had chosen a regular Master Page not the MVC Master Page. What threw me was that I was able to build the program a couple times and run it after I had done this without seeing any errors.