This bug is not currently tracked.
Wim was writing on IRC that strings keep getting unapproved for MDN on Pontoon (fy-NL).
I've tried approving one
It remains approved for me, but it wasn't committed to the repository
There is activity in a few locales within the last 2 days, but no commits
Correction: the activity I saw is suggestions, not translations (for Korean), so it's just Frisian.
I've filed bug 1557666 to track erroneous string extraction on MDN.
I've also disabled Pontoon sync for MDN.
Once bug 1557666 gets fixed, we should re-enable sync for MDN. If that solves the problem entirely, we can close this bug as well.
We should also file a follow-up bug to fail more gracefully when such problems happen in the future. Localizers should be able to keep working on non-broken files, and we shouldn't unapprove strings.
MDN sync works again. Closing as per https://bugzilla.mozilla.org/show_bug.cgi?id=1557666#c7.
I've also filed bug 1558409.