Same issue here "Unknown USB Device (device descriptor Request Failed)"
I'm on OS 8.6.6.32765, RM 3.2.65.17265, and Windows 11 with a kemper stage.
The kemper USB does not connect to my own laptop. However, I just tried on my work laptop which did not previously have the rig manager, and everything seems to be working on the work laptop as it should. I can import my rigs from the kemper, etc.