EntityFramework can't generate DB first EDMX - null reference, cannot load type

Question

I'm using VS2012 and I've done something to break my EntityFramework configuration. The setup and EDMX were working correctly for some time using EF5.

Later I upgraded to EF6 and at that point was forced to make a handful of manual namespace changes to generated code each time I updated the model. But it still worked.

Now I am attempting to eliminate the problem which requires me to change the namespaces each time, but I've broken something.

Currently I cannot generate a DB first EDMX model at all. When I attempt this the wizard proceeds through the steps and then throws an error -- first a dialog about a null reference and then in the VS output:

Unable to generate the model because of the following exception: 'System.TypeLoadException: Could not load type 'System.Data.Entity.Core.Mapping.EntityContainerMapping' from assembly 'EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.
    at Microsoft.Data.Entity.Design.VersioningFacade.ReverseEngineerDb.DbDatabaseMappingBuilder.Build(SimpleMappingContext mappingContext)
    at Microsoft.Data.Entity.Design.VisualStudio.ModelWizard.Engine.ModelGenerator.GenerateModel(List`1 errors)
    at Microsoft.Data.Entity.Design.VisualStudio.ModelWizard.Engine.ModelBuilderEngine.GenerateModels(String storeModelNamespace, ModelBuilderSettings settings, List`1 errors)
    at Microsoft.Data.Entity.Design.VisualStudio.ModelWizard.Engine.ModelBuilderEngine.GenerateModel(ModelBuilderSettings settings, ModelBuilderEngineHostContext hostContext)'.

I have removed EF and reinstalled EF6 with NUGET. I have also tried this in a newly created project with the same result.

Google searches have not been fruitful. Any ideas?

Currently installed version of EF is 6.1.0

Did you install the correct tools for EF 6 in VS 2012? microsoft.com/en-us/download/details.aspx?id=40762 If yes try a repair install. — Rand Random
– Rand Random, Commented Apr 4, 2014 at 22:16
@RandRandom -- the tools for vs2012 and 6.1.0 were already installed. I ran a REPAIR install and sadly the behavior has not changed. — David Tansey
– David Tansey, Commented Apr 4, 2014 at 22:36
@DavidTansey - I think the NullRefException might be a key here. There was a bug in EF6.1 that caused tooling to fail (entityframework.codeplex.com/workitem/2126) but I am not sure if is the issue here. Does it still throw if you restart VS start a new project and try to create a new model for existing database (ideally a different one than the one you see errors with)? — Pawel
– Pawel, Commented Apr 4, 2014 at 22:43
Wow..Restart VS, new project and solution, choose a different DB (a very simple one) and generate -- no change. I'm going to look at that tooling-problem link now. Thanks for your attempt to help. — David Tansey
– David Tansey, Commented Apr 4, 2014 at 22:52

Robert Omete · Accepted Answer · 2014-08-03 14:33:44Z

1

Also tried Visual Studio 2013 with entity framework tools 6.1.1 the same error you speak of persists and you can not create DB first EDMX model. The right solution is to submit a bug report to the Visual Studio team meanwhile uninstall entity framework tools 6.1 versions and install 6.0.1 which will work. EF tools 6.0.1 can be found in your installation media as EFTools in the packages folder.

P.S. Also when you repaired the VS2012 you were actually re-installing EFTools 6.0.1 and removing 6.1.0/6.1.1. You broke up your configuration in the first place by inadvertently updating EF Tools without realizing!

edited Aug 3, 2014 at 14:33

answered Jul 30, 2014 at 6:01

Robert Omete

641 silver badge11 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

David Tansey · Accepted Answer · 2014-04-05 01:47:13Z

0

I was ultimately able to resolve this issue by doing a REPAIR install of VS2012. After the REPAIR install and a reboot I am again able to generate EDMX models.

answered Apr 5, 2014 at 1:47

David Tansey

6,0104 gold badges39 silver badges54 bronze badges

Comments

Robert Omete · Accepted Answer · 2014-08-14 09:56:12Z

0

Entity framework tools 6.1.1 is not working mostly likely if you updated the original 2013 RTM version.It has probably corrupted registry entries. I downloaded the full 6 GB version and installed on a fresh operating system that has never had visual studio, voila it works!

answered Aug 14, 2014 at 9:56

Robert Omete

641 silver badge11 bronze badges

Comments

Farb · Accepted Answer · 2016-11-30 17:24:10Z

0

Try this to fix the problem:

If you use VS2013, then go to:

C:\ProgramData\Package Cache{08AEF86A-1956-4846-B906-B01350E96E30}v12.0.20912.0\packages\EFTools, select the EFTools.msi file, and double-click it to install. This reinstall may solve your problem.

If you use VS2015, then go to:

C:\ProgramData\Package Cache{2A56910C-69C8-495D-8ED8-9080F0A14E58}v14.0.41103.0\packages\EFTools, select the EFTools.msi file, and double click it to install. This reinstall may solve your problem.

edited Nov 30, 2016 at 17:24

answered Nov 30, 2016 at 15:37

Farb

4887 silver badges11 bronze badges

Collectives™ on Stack Overflow

EntityFramework can't generate DB first EDMX - null reference, cannot load type

4 Answers 4

Comments

Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related