Presume you mean XBOX?
Check out XBOX forums, there have been lots of issues since a recent update, including no connectivity to XBOX live and issues with DVD drive.
I had a lot of issues updating and finally sorted this yesterday. Once I got back on, Sky Player had vanished. I tried again about an hour later and it was back. But, I was unable to watch anything. Looks like there's another update coming, so just sit tight.