The type 'Expression<>' is defined in an assembly that is not referenced

Question

In ASP.NET MVC 4.5.2 Framework.

after typing

@Html.LabelFor()
or 
@Html.EditorFor()

in view

I\'m getting Error: The

Answer 1

I did ALL of the above and in the end found that what solves it for me (on a .net framework 4.7.1 site with MVC 5.2.4) was adding this into the root web.config within <compilation> -

<assemblies>
  <add assembly="System.Core, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089" />
</assemblies>

Answer 2

• Close the file
• Clean the solution
• Build the solution
• Reopen the file

Answer 3

I have tried most of these, what eventually worked for me was unloading the project, edit the csproj file, and add the following:

<Reference Include="System.Core" />

https://stackoverflow.com/a/38371981/2335660

Answer 4

I've had the same problem with missing assembly and it happened that VS2017 build has not copied it properly into the Bin folder. These steps helped me:

• Navigate to the web project's References node
• Find the reference to System.Core
• Open the VS Properties Window
• In the properties window, change Copy Local: False to True

from this comment: CS0012: The type '#####Any type#####' is defined in an assembly that is not referenced

Answer 5

I have run in the same issue as you, albeit much later. The issue was that I was not able to access Razor views (.cshtml) as I was getting an error stating that I had a missing assembly reference, namely System.Web.Mvc, even though it was in the project references. After investigation, I have noticed that the installed NuGet version was 5.2.3, while the project required 5.2.0. The solution is to downgrade the MVC version.

1. Go to Project-> NuGet Package Manager.
2. Search for MVC; it's going to be the first result.
3. Next is to select downgrade from the drop-down in the details of the NuGet package and submit.

Confirm all the dialogs and you are ready to go.

Answer 6

This happened with one of my views - all the others were fine. I did the following:

• Create a new view
• Copy and paste the contents from the old view to the new one
• Deleted the old one
• Renamed the new one to the old one