According to a timely-published knowledge-base article on Apple Support, an expired certificate is the culprit. Apple knew about the issue and quietly deployed the patch in its latest software updates for iOS and OS X. A standalone FaceTime update for Snow Leopard users is also available.
Essentially, the fix is performing the latest software update available for your device. But for those users who prefer to stick with a particular firmware / OS version, for example iOS 6, there’s a specific update that can be installed, avoiding to make the jump to the latest firmware. Here’s the lowdown by platform and OS.
How to fix FaceTime on iOS 6 and stay thereSimply downloading iOS 6.1.6 will do the trick, Apple says. No need to upgrade to the latest firmware available today (iOS 7), as some news outlets will have you think.
How to fix FaceTime on iOS 7If you’re on any iOS 7 version below 7.0.4, Apple says to download and install iOS 7.1 or later and the FaceTime issues will be gone. If you’re on iOS 7.0.4 you should be bug-free, but if the FaceTime app doesn’t work for you, perhaps it’s a good idea to apply the latest updates. After all, there are some security patches in there too that might prove vital in the long run. Also, note that by saying “iOS 7.1 or later” Apple is actually referring to iOS 7.1.1. So that’s what you need to install – iOS 7.1.1.
How to fix FaceTime on OS X Mavericks / Mountain Lion / LionSimply updating to the latest version available for each OS will address the problem, Apple says. Whether you’re using OS X 10.9, 10.8, or 10.7, here’s what you need to fix FaceTime:
OS X Mavericks v10.9.2 or later
OS X Mountain Lion v10.8 with the latest security updates
OS X Lion v10.7 with the latest security updates
The latest security update from Apple is Security Update 2014-002 and it’s available for all three OSes. On Mavericks, you can simply update to the latest version of the operating system and the patch will be applied (as the security update is incorporated in 10.9.2).
How to fix FaceTime on OS X Snow LeopardYes, there still are a lot of people running the five-year-old OS on their Macs. Whatever their reasons, they probably like things just the way they are. For them, Apple offers a standalone FaceTime app in the Mac App Store, and the latest version is said to contain the necessary fixes. So download FaceTime 1.0.5 if you’re on Snow Leopard and your connection issues should be fixed.
For customers who still can’t seem to address their FaceTime woes using these instructions, Apple offers document TS3367, which includes more troubleshooting instructions.
Source : softpedia