Only NUnit error: Could not load file or assembly 'EntityFramework' - entity-framework

Question

I get an error message in NUnit when I try to run a specific test. The error looks like this:
ChatProj.Tests.MessageRepositoryTests.Logg_LoggWorking_AssertView:
System.IO.FileLoadException : Could not load file or assembly 'EntityFramework, Version=4.4.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)
Here is a picture
I've looked at the 2 projects in my solution, and I'm refrencing EF 6.0.0.0 in both. I've tried to look up the PublicKeyToken=b77a5c561934e089 and this is what I found in my solution. It's extra weird because I've no problem debugging or building the webapp, and the other unittests are testing within the same project (same EF version) and not reciving this error (as you can see in the picture from before).
Any idea what could be causing this problem?
UPDATE:
I think I figured it out. I was using nuget.org/packages/FakeDbSet which was using a command like : var mockItemList = new InMemoryDbSet { new Message {MessageID = 5000, Name ="Erland", MessageString ="Foo Bar", MessageDate = DateTime.Now} }; which somehow is an old way of faking entity framework code. Can be seen here: i.imgur.com/f6dnJbq.png

Answer 1

First, ensure that the EF DLL is actually getting pulled into the bin folder for the test application. If it is and the DLL is for EF v6, do you see version redirects for EF in your app.config for the test project? Something like this?
<configuration>
<!-- Leave the rest of the configuration file alone and just add the runtime area as follows: -->
<runtime>
<assemblyBinding>
<dependentAssembly>
<assemblyIdentity name="EntityFramework" publicKeyToken="b77a5c561934e089" culture="neutral" />
<bindingRedirect oldVersion="0.0.0.0-6.0.0.0" newVersion="6.0.0.0" />
</dependentAssembly>
</assemblyBinding>
</runtime>
</configuration>
If not, try pasting that into the app.config.
Sorry, it's hard to fully diagnose without more information.