I’m astounded and annoyed.
After a vacation I updated my Unity to 2019.2.9.f1.
Since then I have a massive problem with my project, among other things the code contains the
using UnityEngine.UI;
can no longer find.
The dll itself is present on the harddisk, but after the manual insertion and one build in Unity the reference flies out again.
I already tried ReImport All, but that doesn’t help either.
If I create a completely new project, I can use the dll without any problems.
I am faced with a puzzle
I also tried to install the old Unity version. Unfortunately I also have the bug here now.
I’m afraid that I have to cancel my project.