The symptom is that when you press “Publish” or “Update” to save a page, nothing happens on the first press. You have to press again to get the page to save.

I saw it only on one site, and was able to distill it to this case:
– Twenty Fifteen theme
– Only two plugins: Piklist 0.9.9.9 and my Piklist add-on
– Piklist add-on has one editor metabox that shows up on every page
– Piklist settings have “Accelerate meta queries” and “Javascript Validation” enabled

This happens with any post type that has a metabox with an editor field.

I was able to reproduce this behavior on a different site with completely different database.

It sometimes also fails even if Javascript Validation is not enabled, but I can’t make that happen consistently so it may be pilot error.

Let me know if you want access to my Piklist testbed.

HTH,
Donna