Razor Syntax not recognized

Using VS 2015 Update 3, just installed ReSharper Ultimate 2016.1.2

It seems ReSharper can't resolve the Razor syntax. I'm getting errors like this in the cshtml file:

Cannot resolve symbol 'RenderBody' 

but it does compile and run.

This problem seemed similar to the one here, but the comments in that thread seemed to have gone off topic.

I tried clearing the cache, for what it's worth, as described here, but it didn't work.

I'm also using MVC 6 with ASP.NET Core, if that matters.