Docker Containers can not be stopped or removed - permission denied Error
For anyone that does not wish to completely purge AppArmor.
Check status: sudo aa-status
Shutdown and prevent it from restarting: sudo systemctl disable apparmor.service --now
Unload AppArmor profiles: sudo service apparmor teardown
Check status: sudo aa-status
You should now be able to stop/kill containers.
I installed Docker from the snap package and after a while I decided to move to apt repository installation.
I was facing the same problem and using sudo aa-remove-unknown
worked for me.
So no reinstallation of Apparmor was needed.