after not touching my debian machine for quite some days i did this:
i got this error message:
Traceback (most recent call last):
File "insynclinux/headless/insync-headless.py", line 19, in <module>
File "click/core.py", line 1130, in __call__
File "click/core.py", line 1055, in main
File "click/core.py", line 1657, in invoke
File "click/core.py", line 1404, in invoke
File "click/core.py", line 760, in invoke
File "insynclinux/headless/cli.py", line 360, in status
 Failed to execute script insync-headless
very strange, as i have purchased a license recently.
after rebooting the machine:
insync-headless version shows 18.104.22.16858
insync-headless status brings up the same error message as shown above.