title: System.Web.Mvc.dll added to webforms project
body: <p>I've been working on a webforms application with Visual Studio 2015 Update 3, .Net 4.6, and VB on a Windows 10 PC.  When I do a build and test my app, i'm now getting the error "Could not load file or assembly 'System.Web.WebPages.Razor".   </p>
  
  <p>After doing a compare of the Bin folder with a backup, I found there are 2 additional files: System.Web.Mvc.dll and System.Web.Mvc.xml.  Deleting these 2 files fixes the problem, but I have to do this every time I do a build or publish.  </p>
  
  <p>I've never used Razor or MVC.  I haven't made any major changes except for installing Visual Studio Update 3 about a week before the problem started.</p>
  
  <p>I did a search for MVC in my project and found the 2 files listed in obj\Release\MyApplication.vbproj.FileListAbsolute.txt.  I tried removing them but they are added back when doing a build.  I Tried cleaning and building the project too.</p>
  
  <p>Any suggestions on where to look for a solution?  </p>