I downloaded the latest install from GoToMeeting and resintalled it.
I checked the security and privacy settings, GotoMeeting is checked in every category, so that's not the problem. I jumped on their computers yesterday to see if there was anything wrong permissions-wise. When a presenter shares their screen, these attendees just see black where the shared screen's content is supposed to be.
I have a couple of attendees that are unable to view the presenter's shared screen.