In case you have this stupid error. Google leads you to the following :
- maybe you tried this stackoverflow OWNERSHIP documentation
- maybe you tried this stackoverflow CONFIG Override
- hopefully you did not try the "uninstall / install" thing even if it's often recommanded as a "good" solution... which is not and cannot be.
Of course this can solve your case (except 3.) and I'm not saying this gist is the ultimate solution but that might be something related to a config file that just disapeared (this never happens so you probably made some mistake by copy/pasting commands).
In my case there was a problem in the /etc/systemd/system/docker.service.d
folder. You have to have a file called `docker.c