I have an existing project written in VS2010 which when loaded in VS2010 works perfectly.
When I load this same project in VS2013 the MVC Razor views contain lots of
Update the NuGet Packages using Package Manager console in Tool, Library package Manager..
In command line..
PM> Update-Package
This will update NuGet packages and verify the current version of System.web.MVC and update this version in web.config file under Views folder.
Close the solution and Reopen.
Hope this works !!!