I can't get my phone to work with Yosemite. I seemingly tried everything. I can't check the appropriate box in preferences in facetime. Here's a screenshot. Help!
Well, are both devices signed in to same Apple ID ? (atleast the error says they're not) And/or are your devices on Apple's Supported devices list? Aand is your phone upgraded to iOS 8?
Yes, they were. I fixed it with support and it was quite complicated. I forget exactly what we did but it was in the facetime settings. This is such an awesome feature. The phone rings a different ringtone from all 3 devices so I'll never miss a call again. I had no idea how powerful facetime is.