Modern Algebra's Quest Journal needs a lot of configuration and control (as all quest journal scripts that do more than just check a few switches), but if configured and used correctly, it will work.
That means the error is not in the script, but either in your changes of it (you need to change the script to enter the quest data) or in your event calls to it. So we need to know what you have done with the script in order to find the error.
Please post a link to your modified version of the script, that includes your quests and your configuration.
Also post a screenshot of the event page(s) with the calls to the script.