This solved the issue for me:
chown root:psaadm /opt/psa/var/modules/firewall/firewall-active.sh
You could also go with root:root since it is chmod -rwx------ anyways.
Hi, I get the same error, here is my output of your command
root@server:/# ls -l /opt/psa/var/modules/firewall/firewall-active.sh
-rwx------ 1 psaadm psaadm 3244 Nov 23 2010 /opt/psa/var/modules/firewall/firewall-active.sh