Repeated attempts to repro this have been unsuccessful for me, but I did have hands on a system just now where fail2ban wouldn’t start. I don’t know the cause but it appears to be related to System Admin module
15.0.21.65 - fail2ban fails to start
15.0.21.66 - fail2ban starts like normal
You can get .66 from the stable repo with:
fwconsole ma upgrade sysadmin
confirm sysadmin version with:
fwconsole ma list | grep sysadmin
start fail2ban
systemctl start fail2ban.service
Confirm it’s running with
systemctl status fail2ban.service