Hi Ted.
It looks like that’s an error message with our WooTickets legacy plugin.
While we are committed to solving such fatal errors for our legacy products for several more months, one solution would be to migrate to the product that replaced WooTickets: Event Tickets Plus.
Will that work for you?
If yes, please check out our migration article and get Event Tickets Plus from your Downloads and License Keys pages.
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If you need to stick with WooTickets legacy plugin for now, would you mind grabbing your system information and pasting it here? Make sure to use the “Set as private reply” checkbox to protect your private information from the public.
You can find the system info by going to WP Admin > Events > Settings > Help tab > System Information section
That will give me extra information to help diagnose the problem.