OS X 10.10.2 Your connection failed because the communication device is unavailable. Make sure it's connected to your computerunication device is unavailable. Make sure it's connected to your computer and try reconnecting ad try reconnecting

Send Apple feedback. They won't answer, but at least will know there is a problem. If enough people send feedback, it may get the problem solved sooner.

Feedback

Or you can use your Apple ID to register with this site and go the Apple BugReporter. Supposedly you will get an answer if you submit feedback.

Feedback via Apple Developer

Networking Connection Error

Hi, I have this problem too. It's infuriating. But the solution only works for me temporarily. So, I create a new location, restart, and everything is fine.

Then, a few days later, I decide to turn wi-fi off (maybe I'm on a plane, or in a situation where there is no wi-fi) and that annoying error message starts popping up again. You click 'ok', then it pops up again ten seconds later. It makes working on a plane impossible without having to create another new location and restart.

Why can't Apple resolve this? I don't need an error message telling me I'm not connected to the internet when I've consciously decided to turn the internet off myself!

Any ideas?