Hi

You don't mention what device you are using, but what happens when you rescan for services? Assuming yor Internet connection is ok, its worth power cycling the device by simply unpluggin it for five minutes or so. Then reconnect everything and it should attempt to reconnect to the server and get a content list.

Also make sure you are running the latest firmware, and if none of the above work, carry out a factory reset and it should flush whatever glitch was causing the problem.

Thanks