– What is the broken plugin?
acf
– What is the problem?
it does not save the post and the spinner just turns.
Were you able to watch the AJAX request to validate the data?
– Did the AJAX request ever return data? If so, what was the data?
there was no network activity so no ajax was being sent.
I will look try and recreate on a mirror of the site if you are still unable to get to the bottom of it.
