ajulio
You will need to check all possible logs (general server logs, webserver error logs, PHP error logs, MySQL/MariaDB error logs, osTicket System Logs, Browser Console logs, etc.) for any related errors.
You can see from the code that richtext is hardcoded as a class for this textbox so it should always be loading the HTML editor instead of plain-text. So this points to an error preventing that from functioning properly.
Cheers.
