Facetime not working after Mountain Lion update
I have a Macbook Pro. After I updated to Mountain Lion (from Lion), Facetime no longer works. I've tried with multiple people, but they aren't receiving my calls and I'm not receiving their calls. In Lion Facetime worked fine, but now it's not working. I also can't get iMessages to work. This is very frustrating, because I was really looking forward to iMessages. My Macbook Pro is still new, I purchased it in the first week August (2012). It came with Lion already installed. It's only 2 months old now. So I know my computer can support all of Mountain Lion's features. By the way, I'm running on Mountain Lion 10.8.2. Any help would be great! Thanks
MacBook Pro, OS X Mountain Lion (10.8.2)