I’m not sure if this is fixed in later Unity versions but I am using Unity 2021.3.1 and I was having a problem where Unity would crash whenever I exit play mode. And this went on, on and off for months which lead to me questioning myself why it crash sometimes and other times it doesn’t. Today, I realized what happened; when I enter play mode while the animator window is shown then exit play mode, Unity will crash. If I enter play mode while on any other window, it works just fine. I’m not sure why this is happening
If you can reproduce it in a small project, please file a bug (Help → Report A Bug).
That is the only way to report bugs.
Otherwise the above post is not a bug report and absolutely nothing will be done about it.
Interesting, I have the same problem with 2021.3.x (currently using 2021.3.6f1). My workaround is to make sure the Animator window is closed after making changes.