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.