Gmoccapy RPi4 crash

Hi,
I use LinuxCNC 2.8.2 on my RPi4 with Gmoccapy 3.1.3. From time to when I press certain button in certain situation (I still have not figure the exact combination, it seems to be random to me) gmoccapy crashes and attached error comes up. Do you have any idea what might cause the problem.

Thank you for your time.
Jiri

It might help to Google key phrases from the error message. It is unlikely to be a LinuxCNC specific issue, and there may be clues elsewhere on the internet.

It seems to be some problem with thread synchonization but I have not found the solution yet.

I have never done tests on RPI4 and have not planed to test on RP4.

So sorry, that I can not support.

Norbert