Visual Studio 2019 Wont Compile After Unity 2019.3.12f1 update

I just updated my project to 2019.3.12f1 and I use VS 2019 Community. I am having issues with VS locating third-party DLLs imported from the store. Unity runs fine, but VS will not compile after this update.

Severity Code Description Project File Line Suppression State
Error CS0246 The type or namespace name ‘MMInformationAttribute’ could not be found (are you missing a using directive or an assembly reference?

I am getting the same error with every project DLL.

I am running the latest version of VS2019 Community (as of today). I have Unity Package Visual Studio Code Editor 1.2.0 loaded. All packages are up to date.

Any idea what happened?

Same problem here…

Same here. I tried this: VS Code does not find some classes. cs0246/cs0103 - Questions & Answers - Unity Discussions and it didn’t help. The only thing that’s worked was downgrading to 2019.3.11. I didn’t have this issue with an earlier version of 2019.3 so I believe downgrading to that should work too, but I forget exactly which version I had, probably 2019.3.0.

Please update if you find a solution.

For now though, downgrading to 2019.3.11 seems to be the best option.

2019.3.13f1 does not have this issue for me, so you can now skip 2019.3.12f1, or stay on 2019.3.11f1.
Yay!

This seems to be a common problem, probably a problem with 3.12f1, I’d skip it if I were you and use the next version.