It's very annoying, i keep reporting it as a bug in game, not that anything would be done about it but oh well, getting it since Gyala Delve was added, sadly the only thing that works is to put yourself offline mode, you can't see guild chat or get whispers then but those annoying pop ups doesn't happen if you in offline mode for some reason.
Got it yesterday in strikes once again, its pretty stupid, i'm sure im the only person there who have to add "OK" in my rotation while trying to do the mechanics, went offline mode and it stopped.
Trying to do sab trib mode, 100% sure i will make that jump, jump kittening pop up die.
Play wvw, i get a kitten panic attack when the commander say we have to change map because i know i will change map and have to press OK 101 times before i can do anything else.
Friend who never get those pop ups did a test yesterday to see if he could actually trigger the error, he went and put himself online offline 20x in a row and eventually he got the error, so im not an expert but it seems to have something to do with friendlist/online status.
Anyway if you really want to test this kitten error to the max you should try fractals, sure its horrible in pvp, strikes, wvw, sab, even meta's, but fractals holy kitten!
Edited to add, i never really used the word kitten, i started saying kitten when these 101 bugs started, it made me toxic as kitten.