title: Issue with System.Web.WebPages after installing MVC4
body: <p>I have installed MVC4 and an MVC3 app that I have is now causing me problems.  I get the error :</p>
  
  <p>Could not load file or assembly 'System.Web.WebPages, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference</p>
  
  <p>However, I cannot find any references in my code to v2 of WebPages, and I am wondering why I am getting this error.  Can anybody help?</p>
  
  <p>EDIT : Here is the full stack trace :</p>
  
  <p>[FileLoadException: Could not load file or assembly 'System.Web.WebPages, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)]
     ljMVC.Helpers.EditableHelpers.Editable(HtmlHelper helper, String htmlElement, String cssId, String defaultContent, Object htmlAttributes) in C:\Users\M\Desktop\Development\ASP.NET projects\ljMVC\ljMVC\ljMVC\Helpers\EditableHelpers.cs:90
     ASP._Page_Areas_Gameplan_Views_MainGP_Index_cshtml.Execute() in e:\web\lovelyjubbl\htdocs\Areas\Gameplan\Views\MainGP\Index.cshtml:85
     System.Web.WebPages.WebPageBase.ExecutePageHierarchy() +208
     System.Web.Mvc.WebViewPage.ExecutePageHierarchy() +89
     System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage) +78
     System.Web.Mvc.RazorView.RenderView(ViewContext viewContext, TextWriter writer, Object instance) +199
     System.Web.Mvc.BuildManagerCompiledView.Render(ViewContext viewContext, TextWriter writer) +107
     System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context) +291
     System.Web.Mvc.ControllerActionInvoker.InvokeActionResult(ControllerContext controllerContext, ActionResult actionResult) +13
     System.Web.Mvc.&lt;>c_<em>DisplayClass1c.b</em>_19() +23
     System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func<code>1 continuation) +264
     System.Web.Mvc.&lt;&gt;c__DisplayClass1e.&lt;InvokeActionResultWithFilters&gt;b__1b() +20
     System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList</code>1 filters, ActionResult actionResult) +176
     System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +329
     System.Web.Mvc.Controller.ExecuteCore() +115
     System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) +94
     System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext requestContext) +10
     System.Web.Mvc.&lt;>c_<em>DisplayClassb.b</em>_5() +37
     System.Web.Mvc.Async.&lt;>c_<em>DisplayClass1.b</em>_0() +21
     System.Web.Mvc.Async.&lt;>c_<em>DisplayClass8<code>1.&lt;BeginSynchronous&gt;b__7(IAsyncResult _) +12
     System.Web.Mvc.Async.WrappedAsyncResult</code>1.End() +55
     System.Web.Mvc.&lt;>c</em>_DisplayClasse.b_<em>d() +31
     System.Web.Mvc.SecurityUtil.b</em>_0(Action f) +7
     System.Web.Mvc.SecurityUtil.ProcessInApplicationTrust(Action action) +23
     System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +59
     System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
     System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +8970061
     System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean&amp; completedSynchronously) +184</p>