3D Game Kit has tons of errors showing

Hi,

I'm completely new to Unity. I have tried to pick it up before but to no avail. This time I'm really motivated to start. That if I could...

I'm facing tons of errors in Unity for reasons I have no knowledge of because I will be following beginners tutorials. I have googled but to no avail. I even went as far as installing the same Unity version of the teacher but this also didn't solve my problems.

When trying to import 3D Game Kit I get the following errors and these I have been trying to solve for hours now:

Code (CSharp):

1. Library\PackageCache\com.unity.timeline@1.2.10\Runtime\Animation\AnimationPreviewUpdateCallback.cs(12,14): error CS0246: The type or namespace name 'IAnimationWindowPreview' could not be found (are you missing a using directive or an assembly reference?)
2.  
3. Library\PackageCache\com.unity.ide.visualstudio@1.0.11\Editor\Discovery.cs(5,13): error CS0234: The type or namespace name 'CodeEditor' does not exist in the namespace 'Unity' (are you missing an assembly reference?)
4.  
5. Library\PackageCache\com.unity.ide.visualstudio@1.0.11\Editor\Discovery.cs(35,16): error CS0246: The type or namespace name 'CodeEditor' could not be found (are you missing a using directive or an assembly reference?)
6.  

I have tried to install all available toolkits for Unity, that it may be solve the problem but this didn't work either.

 

Could you confirm exactly which version of the Editor you are using to load this project in? The version number shows in the toolbar at the top of the Editor.