The motor that moves the head side to side isn’t functioning properly.
Common causes:
Rotor motor failure (can’t reach position)
Head needs a reboot or update and may show a false error
Try this first:
Reset the controller
Controller 2: press the green button
Controller 3: press the far-left reset button
Wait 5 minutes, then try running the head again
If it still doesn’t respond, try a full power cycle:
Turn off all schedules
Unplug the controller for 1 hour
Plug it back in and wait 1 minute
Reset the controller
After resetting, run the head again. If the issue continues, open a service case.