I am unable to add a new element or edit any of the legacy hooks. When I click ‘Publish’ or ‘Save Hooks’ I end up on the /wp-admin/post.php page with an ‘Oops! That page can’t be found.’ message displayed. I’ve tried deactivating the other plugins and both WordPress itself, GP theme and GP Premium plugin are all up-to-date. Please help, I need to be able to edit the website!