How to upgrade osTicket to v1.15.4

osTicket v1.15.4 is released on October 7, 2021, its open-source ticket system. You can find full release notes at https://github.com/osTicket/osTicket/releases. For osTicket version v1.15.4 PHP version PHP 7.2-7.4 the process is the same as before just make sure you have a good backup of the database and osTicket files. There are many Enhancements, Improvements, and Security …