If you have made physical changes that the robotics controller can not be aware of, for instance because of a robotics failure or other problem that forced you to open the jukebox and move things arouns, the robotics controller must be reset before normal operation can be resumed. Otherwise, serious problems can occur; the lift may try to insert a tray into a busy slot etc.
Note that a power cycle has no effect, even if it interrupts the current operation, because the Jukebox stores all such events in non-volatile memory. You may notice that the lift still knows where everything is, even after a power failure. Now you know why :-)
