Similar to this question I am using a custom VirtualPathProvider to retrieve views that are embedded in dlls. If I don't put @inherits System.Web.Mvc.WebViewPage on my view I get this error:
The view at '~/Views/Home/Index.cshtml' must derive from ViewPage, ViewPage<TModel>, ViewUserControl, or ViewUserControl<TModel>.
I'm using a custom BaseViewPage that inherits from WebViewPage. Before I started using this custom VirtualPathProvider, setting the new base page in the web.config worked. Now, if I try to inherit my custom class on the page with @inherits My.BaseViewPage I get the same error as above.
For completeness' sake I'll add that the page does start to compile if I inherit from WebViewPage, but it throws an error because there is code expecting the view to have properties from BaseViewPage.
It turns out that the problem had to do with the view engine I was using. To get the VirtualPathProvider working I replaced the view engine with a custom one that added view locations I needed. I accidentally inherited from WebFormsViewEngine instead of RazorViewEngine which is why the error I kept getting was for ViewPage instead of WebViewPage. Now that that's all sorted out my custom base view page works just fine.