Glass Mapper problem with solution upgraded from Sitecore 8.1 to 8.2

Question

We have updated our base solution which just contains a few example renderings from Sitecore 8.1 to 8.2. Note: we are still using VS 2013, but I don't think this should be any problem?

I have updated the references and I think I've tried just about everything in terms of removing and re-adding references, deleting readding and updating Nuget packages.

In my Views whenever I use Glass Mapper editable e.g.

@Editable(Model.DataItemModel, x=>x.HeaderText)

I'm getting x=>x.HeaderText underlined with this error:

Error   4   Cannot convert lambda expression to type
'System.Linq.Expressions.Expression<System.Func<Project.Entities.HeaderSettings,object>>'
because it is not a delegate
type    c:\Projects\SitecoreMVC\Code\SitecoreMVC\Project.Web\Views\Shared\_Header.cshtml

I can't figure out what has changed. Can anyone help?

Answer 1

This error (as well as many other errors) happens because of a mismatch between the used and the targeted versions of ASP.NET MVC binaries.

Sitecore 8.2 uses version 5.2.3.0 of the following assemblies:

• System.Web.Mvc
• System.Web.Http
• System.Web.Http.WebHost
• System.Net.Http.Formatting
• System.Web.Http.Cors

You need to make sure that you have the version 5.2.3.0 of these assemblies:

• for corresponding DLLs residing in your bin folder
• in Web.config under configuration > system.web > compilation > assemblies

• in the redirects in Web.config under configuration > runtime > assemblyBinding, for example:

  <dependentAssembly>
      <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" xmlns="urn:schemas-microsoft-com:asm.v1" />
      <bindingRedirect oldVersion="1.0.0.0-5.2.3.0" newVersion="5.2.3.0" xmlns="urn:schemas-microsoft-com:asm.v1" />
  </dependentAssembly>
  

• in installed NuGet packages

• in references of all of your Sitecore projects

• in Web.config files (if you have any) under /Views and /Areas/*/Views, for example:

  <host factoryType="System.Web.Mvc.MvcWebRazorHostFactory, System.Web.Mvc, Version=5.2.3.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
  
  ...
  
  <pages
      validateRequest="false"
      pageParserFilterType="System.Web.Mvc.ViewTypeParserFilter, System.Web.Mvc, Version=5.2.3.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"
      pageBaseType="System.Web.Mvc.ViewPage, System.Web.Mvc, Version=5.2.3.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"
      userControlBaseType="System.Web.Mvc.ViewUserControl, System.Web.Mvc, Version=5.2.3.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
    <controls>
      <add assembly="System.Web.Mvc, Version=5.2.3.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" namespace="System.Web.Mvc" tagPrefix="mvc" />
    </controls>
  </pages>
  

You also need to ensure that the target framework in all of your projects, as well as in Web.config, is set to 4.5.2.

The error should be fixed after you perform the steps above.