I first installed the Async CTP (Version 3) and then ASP.NET MVC 4 Beta. However, I can't use the async keyword.
Are there any compatibility issues?
There is also a similar question here for ASP .NET MVC 3 (which has no answers at the time of this writing).
Edit: The async/await keywords might be broken before I install any of those. (I am still investigating.)
After uninstalling the KB hotfixes mentioned at this blog spot everything is working normally.