We are attempting to restart the primary hub but it seems to be hung up. The following message is seen in the logs repeatedly:
Jan 4 16:57:34:642  0 Controller: Warning: waiting on probe that has been requested to stop
Release : 20.3
This is related to the following in robot.cfg:
use_force_stop = 0
Determine which processes (either through Task Manager or something like "ps aux" on Linux) are still running.
In some cases allowing a longer time may resolve the issue, but if the probes do not automatically stop, you should investigate (via the probe logs) whether they are busy or just hung up.
If you determine they are hung up you can kill the processes which will allow the robot to restart.
When a robot restarts, it tries to shut down all the probes that are running. If they do not shut down within 10 seconds, the controller issues a 'kill' command based on the PID.
This can be worked around with some configuration settings on the robot. However, adding these settings may cause robot restarts to take longer than usual.
"use_force_stop = 0" is used to prevent the robot forcing stopping probe processes. It will loop waiting for probes to shut down naturally instead.
This is documented here:
Generally it is not recommended to implement this setting in UIM 20.3.3 or later unless advised by support.