DiegoRodriguez
Ahh, you are using an older version which may be the cause (ie. it may have a bug). You are also using an old version of PHP. I would highly recommend upgrading to v1.18.3 but this also requires you to upgrade PHP to 8.2-8.4 (8.4 recommended).
If you still have issues then you'll just have to start looking at your various logs (general server logs, webserver error logs, PHP error logs, MySQL/MariaDB error logs, osTicket System Logs, Browser Console logs, etc.) and maybe even the database.
Cheers.