You need one member of the group who is a friend with all of the other members of the group, and he has to start the group chat (by adding all the other members).
The friends status must be confirmed, ie the others must accept the request-just sending a request is not enough.
Also all the members' privacy settings must be set as the picture you uploaded in case any of them aren't friends with any other of the members.
the user that you are trying to add to a group chat is not on YOUR contact list, so you cannot add them to any group chat.