I have recently started using KStar on a clean install MacOS Big Sur on a 2018 Retina mackbook pro. Celestron Focus motor is the only component that I am having trouble with, the bundled driver crashes every time on FM's calibration. Wonder if this an atypical problem or some one else has experienced it as well.

So I don’t know anything about this particular driver, but I will be glad to rebuild the Mac dmg for you if someone corrects the issue with the INDI driver. Did you try turning on the EKOS focus logging to get more feedback about the crash? Also, are you running the INDI server on the Mac or are you using the Mac as a client and running the server on a raspberry pi?

Also, you could maybe try starting the problematic driver in the KStars device manager and see what kind of output it gives when you change different settings.

I am using the entire KStar setup on the Mac i.e. using Mac KStar's Preferences->INDI-> with INDI Server ticked which gives *Internal INDI Server*.

Sorry, I didn't have time to find where error logging was being done, these pointers save me heaps of time thanks muchly. Shall have the EKOS focus logging and KStar device manager outputs collected when I set the rig up next, quite cloudy next few days in Melbourne.

Been using KStar/Ekos on a Mac for 2yrs.   Never any issue with Celestron Focus Motor(FM), until recently.  Now it occasionally just freezes during normal focusing (not calibration). KStar doesn't crash, just FM is frozen.  I need to reboot Stellarmate to get it back.   And occasionally, after system reboot,  FM is not even recognized by Ekos (ie, INDI Control panel doesn't show attached focuser device).  I may need to rerun Ekos 2 or 3 times, , (or maybe reboot SM, I don't recall exactly) and then it will show.       

I recently installed latest KStar and burned latest SM op system, and this did not solve the issue.   Issue still there.   
Also, in should be noted KStar crashes at least twice a night for me, typically, during other operations too.   So some other issues present too,  but FocusMotor is new unique issue(doesn't cause crash, just freezes).  
I'm desperate to resolve these issues.

Any comments or advice welcome?
(I will turn on verbose logging, and see what I get. )

Verbose focuser logging would help for sure. Please post it when you have it.

I think issue was a loose USB connection. I taped offending connector in place, and so far have not had recurrence.
(On my Ioptron mount, there is one USB port that is not 'snug'; any cable in that port is loose. Hardware issue.)

Thanks.