How to reproduce:
1. Connect one external monitor, set the Laptop's monitor as the primary display
2. Connect a second external monitor and set it as the primary display
3. Create a new project
4. Place the Unity Editor onto the primary external monitor and put it into Full Screen mode (green button in the top left corner of the Editor window)
5. Disconnect the monitor that the Editor is placed on

Expected result: The Editor is resized and placed onto the next monitor
Actual result: The Editor crashes

Reproducible with: 2021.2.0a18, 2021.2.0b7, 2022.1.0a5
Not reproducible with: 2019.4.29f1, 2020.3.16f1, 2021.1.17f1, 2021.2.0a2
Could not test with: 2021.2.0a3, 2021.2.0a17 (causes a black screen without crashing)

Notes:
1. Reproducible only on macOS, because putting the Editor into Full Screen mode is necessary
2. Two or more external monitors have to be connected before disconnecting one of them