The string for "space" is mis-translated for German at the chapter numbering dialog: "Leerezeichen" should be "Leerzeichen".
would you please ping the german l10n team to check this one?
@Kü: can you have a look, please?
I've sent a mail to the l10n list earlier this morning, the team will come back to the issue - Sophie
Fixed it for all versions in Pootle.