Debian – fail2ban not starting jails

I'm going nuts on my live server where fail2ban is not starting jails anymore.

When i start fail2ban, everything looks fine:

fail2ban-client -x start:
2017-11-14 15:51:32,403 fail2ban.server : INFO   Starting Fail2ban v0.8.6
2017-11-14 15:51:32,403 fail2ban.server : INFO   Starting in daemon mode

When i look at the jail status:

fail2ban-client status
Status
|- Number of jail:      0
`- Jail list:

The few lines showing in the log /var/log/fail2ban.log are:

2017-11-14 15:51:32,443 fail2ban.server : INFO   Changed logging target to /var/log/fail2ban.log for Fail2ban v0.8.6
2017-11-14 15:51:32,444 fail2ban.jail   : INFO   Creating new jail 'ssh'
2017-11-14 15:51:32,445 fail2ban.jail   : INFO   Jail 'ssh' uses Gamin
2017-11-14 15:51:33,661 fail2ban.comm   : WARNING Invalid command: ['add', 'ssh', 'auto']

This is a default config, reinstalled fail2ban after a purge.
Anyone knows where i should look?

Running on Debian GNU/Linux 7 \n \l