An amateur error perhaps but hardly limited to free software.

In a particularly expensive piece of enterprise software for the finance sector that was translated into German a form field was labelled 'Hauptstadt', which translates back into 'capital (city)' as in Washington, D.C.

Now, this kind of geographic information doesn't make sense at all in financial software but the well-paid developer (who had to double as the software's translator because hiring a proper translator would of course have been too expensive ...) simply couldn't be bothered to look up the different words 'capital' translates to in German, one of which also is the right choice in that case: 'Kapital' (meaning 'capital' as in 'asset).