Language in title of some workflow transitions is set to 'German' instead of 'English'

All languages settings are in English. Curiously when I do the workflow step and set an issue as "Resolved" or "Closed" the title of the Transition is displayed in German. I checked the value for the property "jira.i18n.title" and it is set to 'resolveissue.title'. I don't know if this has an influence on the behaviour.