Hi @manuel, thanks for this link. I already read it and configured successfully our forum. 
I mean… The Animateurs_DataPaper group is already set as Moderator of the Data Paper category as shown in the screensot below, but in the Permissions tab of the group there is the mention :
There are no categories associated with this group.
I don’t understand the purpose of this sentence since there IS a category for this group.
What am I missing? 