When I open the new Upload OOJS-ui dialog in the wiki in the Hebrew Wikipedia, the strings "Select a file" and "No file is selected" are not translated, even though I'm pretty sure that they were translated in translatewiki a while ago.
This may or may not be related to T119307.
OOjs UI code uses OO.ui.msg() to produce localised messages. Within MediaWiki, that method should be equivalent to mw.msg() (normally, it just takes English strings from a hard-coded list)… but it's not.
We have somehow managed not to implement this during the past two years or so when it could've been needed. It only works within VisualEditor (because it has yet another localisation message implementation when running standalone).
This is neither a WikiEditor or a Multimedia problem. This is a VisualEditor problem because it has a hack for this issue which will need to be removed when I resolve it.
Change 256436 had a related patch set uploaded (by Bartosz Dziewoński):
Connect OOjs UI to MediaWiki's localisation system
Change 256436 merged by jenkins-bot:
Connect OOjs UI to MediaWiki's localisation system
Change 256459 had a related patch set uploaded (by Jforrester):
Connect OOjs UI to MediaWiki's localisation system
Change 256459 merged by jenkins-bot:
Connect OOjs UI to MediaWiki's localisation system