Robot simulator started to crash

I use URSim VirtualBox image on Ubuntu 20.04.4 LTS as a host system.
The Simulator app in the VirtualBox started to crash couple of weeks ago without significant reason - no change in the app or virtual box image has been done. I expect that an update in the host system could be performed in the background but I do know what could be the offender. I found out that I’ able to speed-up the crash by moving the robot in the simulator but I did not find a way how to prevent the crash.

Steps to reproduce:

  • start URSim Virtual box (tested with 5.11 and 5.12)
  • open a terminal
  • launch /home/ur/ursim-current/ (or click to the appropriate desktop icon)
  • robot simulator is started
  • start the robot (Power On - ON - START - (wait to robot is started) - Exit)
  • in the Local mode go to Move page and move robot. e.g. move the base joint to +90 (without this step, app crashes as well but it take longer time (minutes))
  • after couple of seconds the app crashes

Actual Behavior:
the app crash with the error message:
/home/ur/ursim-current/ line 45: 7608 Segmentation fault (core dumped) H0ME=$URSIM_ROOT java -Duser.home=$URSIM_ROOT -Dconfig.path=$URSIM_ROOT/.urcontrol -Djaval.library.path=/usr/lib/jni -jar bin/*.jar

Workaround Suggestion:
no workaround found

I try many to change many settings in virtual box with no effect (CPU, RAM, Graphics, acceleration)
I try to change Virtual box image to 5.12.2 but the behavior is the same
I try ti update virtual box app to newest version 5.1.34 but the behavior is the same

Robot Serial Number:
simulator 5.11.10 and 5.12.2

issue disappeared with the VirtualBox version 6.1.36