I tried to download Cinemachine and got the error below so I removed it and then this error popped up again. Help :(
Assets\Samples\Cinemachine\2.8.9\Cinemachine Example Scenes\Shared\Scripts\InvokeEventFromInspector.cs(6,19): error CS0234: The type or namespace name 'Editor' does not exist in the namespace 'Cinemachine' (are you missing an assembly reference?)