When I tried activating the plesk firewall I am getting below error

Error: Another administrator is activating a configuration now.

To resolve the issue follow below steps:

“Another administrator is activating a configuration now.” error appears when previous activation task wasn’t completed correct.
When activation task is started it creates “safeact.confirm” file in “/usr/local/psa/var/modules/firewall” directory to prevent duplicate firewall configuring task. And after activation finished that file removed. By some reason “safeact.confirm” was not deleted and when you tried to start new activation task it provided an error.

Login to the server via SSH.

cd /usr/local/psa/var/modules/firewall

remove file safeact.confirm

rm -rf safeact.confirm

Try activating plesk firewall now.