Migrated bug from GitHub: https://github.com/Unity-Technologies/InputSystem/issues/153

Sometimes plugging in a keyboard while running Unity editor with the new input system enabled causes the editor to freeze until the process is killed via task manager.
The issue happens only in edit mode (a standalone build doesn't seem to be affected), only with the new input system enabled (Active Input Handling set to "Both" or "Input System (Preview)") and I have reproduced it with 2 out of 3 keyboards I've tested with. No other types of controllers have been affected so far.

I have no 100% repro steps, as the issue occurs seemingly randomly and only on some keyboard devices. Plugging the keyboard in and out while opening or closing the input debugger window and/or entering or exiting play mode repeatedly in between seems to cause the issue to happen more often.

Sorry for a very vague issue report, but I haven't discovered anything else so far. Here is a link to my initial forum post:
https://forum.unity.com/threads/plugging-in-a-keyboard-randomly-freezes-editor.535736/