The language issue in Firefox got worse with the update from this morning, mixing entries in English and French.
After a few tests, it appeared the issue came from the settings in my profile, as creating a new profile has everything in French as it is supposed to be.
After some tweaking, i managed to come back to a fully French output:
- in Settings > General > Language, remove all French language entries
- close Firefox
- make a backup copy of your profile folder (~/.mozilla/firefox/???.default)
- open Firefox
- in Help > More troubleshooting information, click on Refresh Firefox
- let Firefox build a new profile from your previous information; you should now have a language-fixed profile, with your bookmarks but without your customization and extensions
- close Firefox
- empty the new profile folder, except ~/.mozilla/firefox/???.default-???/lock
- copy the whole content of your backup profile folder in the new profile folder, except the lock file
- open Firefox; you should now have a language-fixed profile, with all your bookmarks, customization and extensions
Considering i technically kept the whole content of my profile, the issue might have come from the cached profile instead, but i didn’t try deleting it (Help > More troubleshooting information > Clear startup cache).
