The feature was implemented ingame for Dungeons so it was removed from the addon, but now its missing for the raidfinder because there is still the old filter system.

Could you please elaborate a bit more on what your missing, ideally with a screenshot of where exactly you're missing the members? What version of the game are you playing: Retail, Retail Remix, Wrath, Cata?

If you're talking about the class listing in the tooltip, I did not fully remove the feature, I just disabled the spec listing for dungeons as Blizz is now showing this list:

Here is my (German) raid listing, showing the list of classes:

That was exactly what i meant, retail aswell.
But problem seemed to be on my side.
Cleared the WTF files and reinstalled the addon... now it works.
Apologies and thanks for the quick reply.