So I'm trying to initiate this feature with Message to screen share with someone else. We're both signed into Messages with our apple ID's. I have the option to click it and ask permission for them to share their screen but the other person isn't getting my request? When they try to initiate with me, it's greyed out. We both have the screen share enabled via system preferences. Mine is a Mac Mini and theirs is a MBP both latest versions of Yosemite Any other suggestions?