If you are speaking about the LEDs that are part of the CC3D board (or extra WS2811 LED added with a wire cable), then if they go out (turn off) it usually means that the power to the CC3D has gone out.
Or maybe you are speaking of LEDs that were added by manufacturer on this drone that LibrePilot software does not know about?
If you can determine the kind of LED (usually simple LED or WS2811 LED) and where it connects to the CC3D, then maybe we can understand your problem better.