Plesk support SSH Access extension displays warning: Some issues were detected: Cannot whitelist IP address: Binary sa-fail2ban.sh execution failed with error code 255

Symptoms

• After granting access via Support SSH Access extension, the following warning is displayed on the screen:
  

  PLESK_INFO: Support SSH Access extension displays warning: Some issues were detected: Cannot whitelist IP address: Binary sa-fail2ban.sh execution failed with error code 255; stdout [Sorry but the jail 'ssh' does not exist ] stderr [2021-11-04 16:29:17,829 fail2ban [377714]: ERROR NOK: ('ssh',) ]

• Jail 'ssh' is disabled at Tools & Settings > IP Address Banning (Fail2Ban) > Jails.

Cause

This is an expected behavior. When you grant access to SSH via extension, it executes a script to add required networks to fail2ban. If the SSH jail is not active, it produces a warning and the networks are not added.
Nevertheless, an internal request with ID #PPPM-13288 was created to address the warning in question.

Resolution

1. Log into Plesk

2. Enable the 'ssh' jail at Tools & Settings > IP Address Banning (Fail2Ban) > Jails.

3. Go to Extensions > My extensions > Support SSH Access and click on the button Revoke access immediately.

4. Grant access again.