Topic: TotalMixFX 1.64 doesn't quit on MacOS 10.11.6

Every now and then, TotalMixFX doesn't properly exit after closing its window and can't be killed nor restarted, only solution is to reboot. In fact, it is in a process state of "E" meaning "trying to exit", and no "kill -9" will remove the process.

schwarz            598   0.0  0.0        0      0   ??  ?E   16Jan20   0:00.00 (TotalmixFX)

This is with
Fireface 400 (over a Thunderbolt adapter)
firmware 1.71
TotalMixFX 1.64
Driver 3.38
MacOS 10.11.6
MacBookPro 13" mid 2015