440 error on recurring events with a past date

Clicking on the “See all” occurrences link of a recurring event with Events Calendar Pro can give an error 404 page under the following conditions.

* The Post Types Order plugin is installed, activated, and has the “Auto-sort” feature checked.
* The recurring event has at least one date in the past.

I don’t see messages in my debug.log, so, I’m not sure what is going wrong.

Post Types Order is a reasonably popular plugin (300,000+ installs), and actively maintained, so, others may have run into a similar problem.

For now, I have resolved my issue by un-checking the “Auto-sort” feature in the Post Type Order settings, and, have followed their instructions for applying it to only specific post types. I hope this helps someone else from tearing our their hair.