Been getting this error message when editing a post and then choosing "More Options".
Happens on both mobile and desktop.
Well, I've got news on this front. I looked into things, traced it to xenforo's editor. Went for a look in their customer support forums, and guess what?; Known bug, and basically no good solution to it. It was reported to google as well, and they tagged it as "won't fix", because it happens to have the same pattern that a vulnerability would have. Which is fine and all, since their priority is security, but puts people using it legit in a bit of a bother.
My options are basically this:
a) I write a plugin to detect the specific scenario and make it forward chrome users to the full editor instead. "Best" solution, but it's time consuming. Probably too time consuming. I'm hoping someone with more time and experience on this flavour of thing gets on it and I can patch xenforo with their stuff, because right now, it's just not viable for me to spend the time fixing it myself, with BB coming really soon.
b) I mess with things to disable the auditor. It means stuff will be back on "business as usual" mode, but it might not stick for long (or at all), and it's insecure as hell. I'd be basically tying the guard dog to a lamppost with a one foot long leash. It prevents it from biting the mailman, but it also prevents it from biting the guy looting your house. I like this plan least of all.
c) I disable in-line editing completely until we get a hold of XF2, which I'm told has enough changes in its structure to make this bug irrelephant. XF2 will happen at some point "in the future"; this means that every time anyone, in any browser, needs to edit a post, they get sent to the full editor. It's a slight loss of functionality, and not something I'm keen on, but if I need to choose between faster editing and safer users, I'm gonna have to go with the later.
I'll be flipping the switch to disable inline edition in a bit, then. Hopefully a plugin-based fix comes soon and we can make it so chrome degrades gracefully instead of erroring out on people.