This page has missing translations or rather - missing translation strings altogether:
https://www.inaturalist.org/taxon_changes
The problem manifests in English, Bulgarian, Polish and others, but not in Russian.
Looking at the translation files, the string “on_” is missing in the corrupted languages:
https://github.com/inaturalist/inaturalist/blob/master/config/locales/en.yml
but present in Russian:
https://github.com/inaturalist/inaturalist/blob/master/config/locales/ru.yml
Keywords: “translation_missing”, " en.on_", " Committed On "