There seems to be a bug in the DM Control Panel page (or just Internet browser incompatibility) as I always get that error. What really matters is if you get the Create Invitation button, in which case you are eligible for creating an invitation. If you click on it, it will still generate the invitation and send it to the email address you specified within the Control Panel...
well it seems i'm able to create sum mo invites , PM if u really, really need it....!! i'm really sorry for the time being absent but troubles that arose within my Fortitude of Family prevented it, to say the least but then again, one Sunday i spend on MDL the other i suddenly go for a stroll with my kids....