Why can't I install Unity UI Toolkit?

Question

I want to use UI Toolkit for my project.

When I try to install it using com.unity.ui something strange happens.
When the installation is finished, the package appears and immediately disappears from my manager.

I'm using version 2021.3.6f1.
Am I doing something wrong?

Answer 1

You don't need the com.unity.ui package in 2021.3 anymore. While UI Toolkit was always a core module in Unity, the Runtime (the UIDocument MonoBehaviour) support that com.unity.ui added has also been moved as a core module in Unity in 2021.x. You should be good to go!