Editing terrain becomes slow and editor crashes

Unity: Optimization

2023.2.X

2023.1.X

2021.3.X

Fixed an editor crash that can happen when editing terrain.

Does not happen prior to 2023.1

Users report that raise and lower terrain causes "Hold On" dialog in editor. Internal users have same behavior.

When I did some testing around this I was able to produce an editor crash.

Internal discussions

Update - this appears to be a problem in the UndoManager.