Anything that uses the revtag table (transver, fuzzy tag, translatable pages with tags/marks) is getting broken in various way due to revision id getting overflow.
See also https://www.wikidata.org/w/index.php?title=Wikidata:Translators%27_noticeboard&diff=0&oldid=2108897068
= Original report
== Steps to reproduce
1.* Edit a translation unit manually to prefix it with `!!FUZZY!!`. //[[https://www.wikidata.org/w/index.php?title=Translations:Wikidata:Events/47/es&diff=2151698459|Example.]]//
== Actual result
2. `* `!!FUZZY!!` appears literally in the translation page source. //[[https://www.wikidata.org/w/index.php?title=Wikidata:Events/es&diff=prev&oldid=2151698482|Example.]]//
== Expected result
2.* The translation unit is wrapped in `<div class="mw-translate-fuzzy">` (assuming it’s a block translation unit and doesn’t have `nowrap` attribute). //[[https://www.wikidata.org/w/index.php?title=Wikidata:Events/es&diff=2144511543|Example from a week ago]], when it still worked.//
== Software version
Regression from 1.43-wmf.4 (T361398).
== Impact
It’s unfortunately fairly common that newbies/anons press //Confirm translation// in Tux even though the translation clearly needs to be updated (in this specific case, a complete sentence is simply missing in the translation), probably testing the interface. Before this regression, manually prepending `!!FUZZY!!` could partly revert these otherwise unrevertable edits (only partly because the diff no longer appears in Tux, since Translate no longer knows when the translation was really last updated). Now I don’t think it’s possible to revert these test edits even partly.