Hello and thanks for the question,
We have many customers currently (and successfully) using our ticketing plugins for booking online workshops, music festivals, and tons of other instances 🙂
To answer your question – the error you described sounds like a possible theme and/or plugin(s) conflict rather than coming from our plugins. We extensively test for possible conflicts before releasing new versions. If a bug is found, we log it and address it based on priority. The error you described would be considered a “top priority” and would most likely be fixed immediately after it’s initial release.
I would recommend turning on wp_debug in your wp-config.php file to help find the conflict you’re having.
Thanks for contacting us and I hope to see you around in the support forums. Have a great day!