Not that it stopped me from the install. :) I did not see this mentioned already so my apologies if this has already been posted.
It's part of: https://github.com/elkarte/Elkarte/issues/1641 :(
And this should fix it: https://github.com/emanuele45/Dialogo/commit/9f48e188af6c07e5d55382c033e2dcbaae05fb0a
At least styled the message box for this release :P Sorry for the trouble there, damn, another version compare in the code!
With the fix at least I squashed one, even though I wasn't able to remove entirely the code because it's used somewhere else.
I'll open an issue to track the improvement of that javascript bit.