Microsoft (R) Visual C# Compiler version errors

Questions & Answers
1

So, my journey with Unity started from version 2018.4.32f1. I earned there some experience and after few months, I decided to move to version like 2019 or 2020. Firstly I installed version 2019.4.8f1. I created new project, run it and first thing I got is this compiler error:

Microsoft (R) Visual C# Compiler version 2.9.1.65535 (9d34608e)
Copyright (C) Microsoft Corporation. All rights reserved.

And I thought - “It’s okay I’ll then install version 2020.3.1f1”. So I installed this version and then I got this similar error:

Microsoft (R) Visual C# Compiler version 3.5.0-dev-20359-01 (8da8ba0c)
Copyright (C) Microsoft Corporation. All rights reserved.

I don’t know what to do. I don’t want to start my “gamedev career” on old version of Unity. I would be really grateful if someone could help me solve it. Please…

4

When I got that error, I fixed it by:

  • Changing any of my scripts’ folder/moving it away from the folder that’s in
  • And then returning it to its original folder. If the issue didn’t go away, I repeated the same thing that fixed the error.
5

Not need to change the script’s folder. Just type something in the script and save it then undo your type and then save it again. That’s all

2

Sorry no help from me, I have the same problem (have you solved it yet?)

3

Ok, so formatting disc C: and reinstalling whole system seams to solved the problem. I still don’t know what exactly was wrong but…if it works then don’t touch it ¯_(ツ)_/¯. I hope that it won’t happen again…

6

Solution is there:
https://stackoverflow.com/questions/56913616/unity-2019-3-0a7-microsoft-visual-c-sharp-compiler-errors

Uninstalling Anaconda and Python can result in such issues because of remaining artifacts in the Windows registry.

In my case, removing the following key in Registry Editor worked :

Computer\HKEY_CURRENT_USER\Software\Microsoft\Command Processor\AutoRun

It was targeting a file removed in the Anaconda uninstall process.

7

heh restarted unity it went away

8

That pop up after I pull some changes from others dev and It was about API compability level under the Project - Player settings.

I changed API compability level to .NET Standart 2.1 and its fixed.