Okay, after using the raid window twice, there is some sort of bug that involves people leaving the group, then leaving the raid, after which no one can invite them (say's they are not in a raid or you can't invite because you're not a leader blah blah blah). I'm not totally sure of the cause, or the solution, but we've fixed it by basically disbanding raids a ton, disbanding groups, and camping out. It's a real hassle and time sink, but I know other people out there have used the window more than us. So, if anyone can elaborate on what exactly causes the bugs in the first place, and how you can resolve them that would be helpful! Thanks!