Hi Kirsty,

for me the solution was rather simple in the end. No techie stuff :)
You should just create another admin user, and when you log in with that new user, the Advance Editor should be working again. I hope it works for you too.

Hi, I’m having just the same problem here. I’ll describe some things hoping that it helps shedding some light on what this bug might be.

It’s curious because the Advanced Editor works fine in the Post Editor, while in the Pages Editor it crashes. Earlier I rearranged the option boxes in the right column (publish, page attributes, layout). Initially it worked fine, but when I added an Animated Countdown to the layout, it suddenly crashed. I’ve tried to use that element in the past and never worked but at least, the Advanced Editor could still be used. The only thing that was different this time was the right column elements order, as I mentioned.

These boxes can no longer be re-arranged, nor folded, but their content is functional. For instance, I can browse older revisions, pick a previous one, but still, when I’m back at the Edit Page, there’s this loading gif below the Avia Layout Builder. The Default Button doesn’t either work.