I am in the process of upgrading to MVC4. I have followed the instructions at http://www.asp.net/whitepapers/mvc4-release-notes#_Toc303253806 but in my Razor views and layou
I've encountered this specific issue as well; no (or incorrect) intellisense showing when trying to use razor tags. My specific issue was VS2015 complaining that Html.BeginForm was not existing in the current context.
I've got areas set up in my MVC project, and managed to narrow down the cause of my error to the web.config file for a specific area, rather than the global web.config.
It turns out that the cause of this issue for me was that I'd added a SQL connectionString into the web.config for the area that was not working, this (I am assuming) caused a parsing error, however the project compiled up correctly.
Moving the connectionString to the global web.config has rectified the issue. Hopefully this may be of some use to others.