OK, this is bad, but unless we have some steps to reproduce this is going to be really hard to fix. :-\
Actually, could you check the Error Console for stuff when this happens? I bet somehow the highlighting thing is failing, and that should give an error...
I guess the "critical timeline" bit means I couldn't persuade you to binary test versions inbetween these two to figure out where in the past year and a half we've screwed up? :-(
We can try a binary if you like but I'm not sure how much time we will be able to put into it, especially since the error seems to be somewhat random. I will say thank you thought as we have received VERY prompt responses to this and another bur report we submitted. Thanks for the dedication and follow through.
Created attachment 290996 [details] Non-working test So I tried to repro this myself using the attached thing, and am not having much luck at all. Can you yourself trigger it with this file?
You need to log in before you can comment on or make changes to this bug.