Hello. My name is Michael. I can help you with your question if you still need assistance.
It is likely that the disc is not loaded into the tray properly. However, it is usually safe to unplug the printer and then gently slide the tray out - when you put the tray back in to print, make sure you push it slightly until you feel that it has set into place. You don't have to push it too hard, but you will feel it when it is all the way in. If you just place it there as you normally would with paper, it won't be able to pull it through. Please let me know if this helps or if you need additional information.