It shouldn't be a difficult thing for Visual Studio to whip up a controller class for you, right? "Save me a few seconds of typing, won't you, VS old buddy? Why don't you drop a FooController.cs in that there folder!"

And VS promptly locks up. Hope you saved everything.

This guy has the explanation:

... and it basically comes down to the OS putting the "block" on files coming from "untrusted sources" like the Web or something (like, say, NuGet packages). When this happens to you, you do a "Properties > Unblock" on your download and you're good - but for whatever reason, this isn't something VS can pull off on it's own.

Check out the blog post for more details.