Edit: After half day, my wife’s Mac started having the same problem. I have then applied the solution that I found in the Apple
Apple TV Refresh Coming With In Months. As Current Generation Apple TV Out Of Stock –
There has been a lot of conversations involving both the words Apple and TV over the last few months and the current rumors are suggesting we will an actual Apple TV late this year or some time in 2013. But we have did a little bit of research to find out that stock levels for the current generation Apple TV set top box are extremely low and in most cases none. We have contacted some of the retailers are they have said
We are unable to stock back up as the Apple TV is currently unavailable from the manufacturer
This message is also shown on the Target website.
This could suggest we will see an update/refresh of the Apple set top box at the rumored March 7th media event which is said to be when Apple will show the iPad 3. If you are looking for an current generation Apple TV your best bet is to check your local stores by visiting them as most online retails are out of stock.