Devices capable of running iOS 7 must be upgraded to iOS 7.0.4 or later, while devices unable to run iOS 7, such as the fourth-generation iPod touch, must upgrade to iOS 6.1.6.
If you started to have issues making or receiving FaceTime calls after April 16, 2014, your device or your friend's device may have encountered a bug resulting from a device certificate that expired on that date. Updating both devices to the latest software will resolve this issue.
If you're using iOS 7.0.4 or later or iOS 6.1.6, this issue doesn't affect you.
If you're using these versions of OS X or FaceTime for Mac, this issue doesn't affect you:
- 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
- FaceTime for Mac version 1.0.5 or later for Mac OS X v10.6
While FaceTime does work with iOS 6.1.6, that particular update is not available to recent devices that are able to run iOS 7, which means iOS 6 users with newer devices who wish to access FaceTime must upgrade to iOS 7. Read http://support.apple.com/kb/TS5419