Coincidentally, I recently encountered a similar issue on the website of a user. I haven’t been able to investigate it, and I can’t reproduce it, but I know on which line that particular issue occurred.
If this has the same cause, the problem occurs when the plugin tries to do a one time flush of the rewrite rules.
Could you try changing in class-admin.php, in line 97,
add_action( 'admin-init', 'flush_rewrite_rules');
into
add_action( 'shutdown', 'flush_rewrite_rules');
And let me know if that works for you? If not, you can comment it out/remove it.
Yes, that worked perfectly! Thanks very much. Awesome plugin and great support!
Hi @stevenkellow,
Thanks for the update! It’s good to know this fixes it.