Items in your XOGO playlist can be configured as visible (this is the default) or invisible (so they only appear when triggered via Realtime mode). You can tell when something is invisible because it will have an image of a crossed-out eye, as shown below.
The Problem
If you have set all items in your playlist as invisible, your XOGO player will have nothing to display when it is not in Realtime mode.
Solution
Open XOGO Manager
Click on your playlist
Set one or more of your media items as visible
Click Save