“Your connection failed because the communication device is unavailable. Make sure it’s connected to your computer and try reconnecting. “

Girl.luvzer.Mac has the solution.

Try this: Go to System Preferences>Network . At the top of this window, it probably will say Location:Automatic. Click that drop-down box and choose “Edit Locations”. Click on the +, and create a new location.

If you’re on Airport, it may ask you for your network key again- enter this.

Restart and see if this has fixed it.

via Apple – Support – Discussions – Networking Connection Error ….