osTicket Version: v1.11 (d4e240b) — Up to date
Web Server Software: Microsoft-IIS/10.0
MySQL Version: 5.7.25
PHP Version: 7.0.21

Upgraded from 1.10.4, no problems.

Now I try to add an email address to the banned list. The message "Unable to add the email to banlist" is displayed.

In Admin panel I go to Email Settings > Banlist. Only the latest (attempted) additions to the list are shown, and there is a message on the pages saying ""SYSTEM BAN LIST filter is DISABLED - enable here". Clicking there takes me to the email filter page which is showing the filters I added myself. There is nowhere on that page to do anything about the system ban list.

However, based on log entries, the system ban list is till operational using addresses that were previously added but which are now not showing on the ban list.