Hi,
Please can you clarify your issue as you can't add layer packages to Explorer Online (the web version)? If you did actually mean service then can you provide the url to the service so we can have a look at it? If it's not publically accessible, please post the service description (you can get this by clicking the arrow to the right of the layer in the contents window, then clicking on the 'Service Details...' button.
Also you could make sure there is data where you are identifying by trying to do the same thing in another client applications (e.g the map viewer on ArcGIS.com > Make a Map)
Mike Rudden
Esri
