GoPiGo3 control_panel_gui_3.py Save and Exit - not

After updating successfully, I see the new GoPiGo3 Control Panel app.

I am unable to set my GoPiGo3 wheel and wheelbase parameters in the control_panel_gui_3.py desktop program. (It does not do anything after clicking “Save and Exit”)

There is no error reported to the stdout:

pi@Carl:~ $ python /home/pi/Dexter/GoPiGo3/Software/Python/Examples/Control_Panel/control_panel_gui_3.py
Xlib:  extension "RANDR" missing on display ":1.0".
pi@Carl:~ $ 

I added to onSave():

except Exception as e:
            print("onSave exception {}".format(e))

and see

onSave.try.set_robot_constants
onSave exception [Errno 13] Permission denied: '/home/pi/Dexter/gpg3_config.json'
pi@Carl:~ $ ls -al /home/pi/Dexter/gpg3_config.json
ls: cannot access '/home/pi/Dexter/gpg3_config.json': No such file or directory