When using invisibility, “fatigue “accumulates, when a certain level is reached, it becomes impossible to use invisibility, the more” fatigue”, the more “rollback”. Fatigue is removed gradually by itself, after restarting the server, when passing the gate between the systems, after passing the “wormhole” and in the dock.
Fatigue is only in the “zeros”, in the empire and wormholes it is not needed.