Issue fail2ban jail error

[Remigio]

I've debian 9
when I try to click on fail2ban-->jail--> f2bmng failed: ERROR:__main__:Command '['/usr/bin/dpkg', '-S', '/etc/fail2ban/jail.conf', '/etc/fail2ban/jail.d/plesk.conf', '/etc/fail2ban/jail.local']' returned non-zero exit status 1.
Follow also this docs: Fail2ban cannot to enable jail due to errors in configuration on Plesk
and also Unable to activate or remove Fail2ban: error reading information on service fail2ban: No such file or directory (rpm command not found)
not solve my issue

 

[Bitpalast]

Maybe you can find more details in the /var/log/messages log file or the /var/log/fail2ban.log file.
I think that it is likely that the jail cannot be started, because there are no log files that it can process. For example, if a jail only processes website logs of domains that start with the letter "a" and there is no such domain, the jail cannot start, because there are no files it can find to process them. Depending on your specific configuration this can or cannot be the case. Normally, more details on the reason why fail2ban cannot start should be available in the system logs as mentioned above.

 

[Remigio]

can you take a look at my fail2banlog here fail2ban.log
and messages messages
it seems to be work well, so I don't know why that error.

 

[Bitpalast]

I can identifiy an issue with the IMAP (dovecot) fail2ban support in your logs. Please follow the solution of this article:
Fail2ban errors: iptables v1.6.0: invalid port/service imap3 specified

 

[Remigio]

Thank you very much @Peter Debik
Problem is when I try to enter into fail2ban-->jail I've this error <<Errore: Impossibile ottenere la lista di jail: f2bmng failed: ERROR:__main__:Command '['/usr/bin/dpkg', '-S', '/etc/fail2ban/jail.conf', '/etc/fail2ban/jail.d/plesk.conf', '/etc/fail2ban/jail.local']' returned non-zero exit status 1.>>

 

[Bitpalast]

I think you are looking for a solution "cannot access list of jails". It is probably described here:
Unable to access Jails list of Fail2Ban: ERROR: f2bmng: No option 'enabled' in section
However, I am not sure, which jail is causing the problem in your case. Maybe it is the dovecot jail.