Hi @daveb123,
I can confirm the issue in Easter page, the reason for that is the response for ajax request for /x/ is blank. It could be the existing data of that page is already broken. You can see in this screenshot that some section are non-functional anymore.
Box icons instead of arrows indicating a sub-structures. Viewing the page on the front doesn’t reflect the number of sections in comparison to the builder view as well. This doesn’t happen on other pages nor on new pages, hence, this is specific to the page data in which already broken. Same issue if you duplicate the same faulty page since the broken data is carried too upon duplication.
And with broken data, the preview is not going to execute well causing the internal error, hence, /x/ response became blank.
Would you mind providing your FTP login credentials as well so I could directly check if there is an internal error being logged? I can’t promise any solution, but your last option would be re-creating the broken page.
Thanks!