Next to parts in French the whole series was taken in German.
So there ist not much interest to have German subtitles.
But for non German natives it may help to watch and to learn German.

The RORIK film on DVD got German and English subtitles
but the older two DVD set with all the episodes came without them.

Never the less there are German texts of all the episodes
typed by several fans. So, with a lot of work for the timestamps,
subtitles could be added to the DVD set.