asp.net mvc - CS0234: Mvc does not exist in the System.Web namespace

Question

I converted a ASP.net 4 webform project to Asp.net MVC4 according to Chapter 13 of the Professional ASP.NET 3.5 MVC, by Scott Hanselmen, Phil Haack, and Rob Conery, Published by Wiley Publishing, Inc. (ISBN: 978-0-470-38461-9). I also followed this blog. Now I can add Controllers, Views, etc. All the references are set properly. No build errors. But upon launching the converted project, I got compilation errors. I have mvc3 installed on the same machine. I even changed the reference to that. It still complain. Could you help? Thanks.

Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately. 

Compiler Error Message: CS0234: The type or namespace name 'Mvc' does not exist in the namespace 'System.Web' (are you missing an assembly reference?)

Source Error:

Line 109:            <namespaces>
Line 110:                <add namespace="System.Web.Helpers"/>
Line 111:                <add namespace="System.Web.Mvc"/>
Line 112:                <add namespace="System.Web.Mvc.Ajax"/>
Line 113:                <add namespace="System.Web.Mvc.Html"/> 

Source File: c:UsersJonDocumentsVisual Studio 2012ProjectsCMTAppsBranches3.0Web.config    Line: 111 

Answer 1

I had the same problem and I had solved it with:

1.Right click to solution and click 'Clean Solution'

2.Click 'References' folder in solution explorer and select the problem reference (in your case it seems System.Web.Mvc) and then right click and click 'Properties'.

3.In the properties window, make sure that the 'Copy Local' property is set to 'True'

This worked for me. Hope it works for someone else

Helpful Note: As it has mentioned in comments by @Vlad:

If it is already set to True:

1. Set it False
2. Set it True again
3. Rebuild