Thanks for your invitation. I accept being a contributor to "IndieGuild" group but I'm having an issue. When I press the button "accept" I get the message from deviantart: "Sorry, you are unable to join this group. You are already an administrator of three or more groups. ...upgrade to Premium Membership first". In fact I am the founder of three groups and did not understand why I can not be part of another group as contributor ... Does there exist a way to be able to contribute?