Items in your XOGO playlist can be set to visible (this is the default) or invisible (so they only appear when triggered by Realtime mode). You can tell when something is invisible because it will have an image of an eye with a line through it, like below.

If you've set all of your playlist items to be invisible, your XOGO player will have nothing to display when it's not in Realtime mode. To fix this open XOGO Manager, click on your playlist and set one or more of your media items to be visible, then click Save.