There are 95 errors reported today:
ResizeObserver loop limit exceeded
There doesn't appear to be much further detail. I see Special:Translate as a frequent URL but not the only one.
A few possibly related errors:
ResizeObserver loop completed with undelivered notifications.
This is reported from regular articles on both fr.wikipedia and he.wikipedia. The samples I checked were not in edit mode and the articles also both did not contain any audio or video. Hence it seems related to neither CodeEditor nor TMH.
Eg.:
@Niedzielski What led you to suspect those two?
@Krinkle, the only relevant ResizeObserver usages I could find in WMF code were in CE and TMH. The issue could also originate with on-wiki code,
I'm only seeing about 8 of these errors in the last 7 days. Given we're live on more wikis now it may be fixed. At this point this is just log spam and I reckon we'll filter these out once we have a solution to T266054.
Resolving as fixed pending it turning out that these came back in larger numbers.
Note that if there is a ResizeObserver-related bug in TimedMediaHandler it'll be releated to video.js, and numbers may go up in a few weeks once we push the new frontend out of beta. If so, reopen. :)