mvc 4 assembly reference missing for Json.Encode
- References in solutions explorer > right click > Add reference
- Under Assemblies > Framework, search for "System.Web.Helpers" Double click
- System.Web.Helpers version 2.0.0.0 and click ok. Find the
- System.Web.Helpers you've just added > right click it > properties.
- Change "Copy Local" from false, to true
And now @Json.Encode should work.
Update
To be clear, even after you add the correct reference to your project, you still have to add this line at the top of your Razor page:
@using System.Web.Helpers;
Apparently if you create a new empty web project, and try and move everything into Areas, it removes the Helpers library. But if you create it as an internet project, they remain. I created a new project as an internet project and everything works now.