EntityFramework 5 - Getting value cannot be null parameter name: font error while using the designer

Question

I'm getting a strange error while using EF 5 using a Database First approach on the designer. The error is saying 'value cannot be null parameter name: font'. I also get a big red X over the design area. I'm not exactly sure how the designer generated this error, and to this point, I've only used the designer to create my edmx.

Thoughts? This is with VS 2012 RTM version.

Windpollinated

Can you just delete edmx and add a new one? – Maenad

Are you sure your VS installation is not broken? Looks like some resources are missing... – Todd

I even don't know EF 5 supports EDMX. I thought only EF 4 was with EDMX. – Peculation

Answer 1

I was able to resolve the same error by simply restarting Visual Studio.

Violinist

Yup. Three years later, and this bug is still alive and kicking in VS2013. It's good to be consistent...!! Oh, and restarting VS2013 fixes the issue. – Gulch

...and we're now in mid-2017, and the bug is still alive in VS2015 Update 3. – Gulch

Just observed this bug today in VS 2017 on a .net 4.0 project. Closing VS and then reopening fixed the problem. – Josphinejoss

Answer 2

I was able to fix this by repairing the Entity Framework Designer for Visual Studio 2012 (Control Panel -> Uninstall a program etc..)

Dorkus

Answer 3

I just had exactly the same problem (several years later) after I started using Entity Framework designer right after installing it. (using VS2019, .NET Framework 4.7.2, and Entity Framework 6)

I the issue disappeared, before I could document it:
Restarting Visual Studio only one time was not enough; I did it few times. I'm not sure why, but it is likely because that some VS components did not unload right away when I was just restarting it.

I guest it would have work right away by restarting the computer, to ensure everything is unloaded from memory.

Thanks to SausageFingers for the clue.

Sil