This is the message from wordpress
Error Details
=============
An error of type E_ERROR was caused in line 584 of the file /var/www/html/wp-content/plugins/post-grid/includes/classes/class-meta-boxes.php. Error message: Uncaught Error: Call to undefined method settings_tabs_field::admin_scripts() in /var/www/html/wp-content/plugins/post-grid/includes/classes/class-meta-boxes.php:584
Stack trace:
#0 /var/www/html/wp-admin/includes/template.php(1389): post_grid_meta_boxs->post_options_display(Object(WP_Post), Array)
#1 /var/www/html/wp-admin/edit-form-advanced.php(688): do_meta_boxes(Object(WP_Screen), 'normal', Object(WP_Post))
#2 /var/www/html/wp-admin/post-new.php(75): require('/var/www/html/w...')
#3 {main}
thrown
Welcome to our forum.
I understand the issue, do you use any other plugin from us? or you probably still using older version of plugin, we have already fixed this issue in latest version.
Regards
Also, can't make a post or page without turning off post-grid. Is it interfering with the classic editor? Really odd.
All are updated – Post Grid, Post Grid Pro, and Accordion Pro. I did that before posting a ticket.
Turning off Accordions fixed the problem.