Do you mean xPro? https://openbuilds.com/threads/cnc-xpro-v3-controller-stepper-driver-fault.9353/#post-64644
Per Mike from Sparks Concepts: >>The LEDs are there to show motor power for each coil (red is coil A and green is coil B) - all this means is you have power going to the motor. On startup previously your B coil was energized, now your A coil is. The thing to note, with micro-stepping enabled there are a couple microsteps where both LEDs will be very dim but light up when the motor moves to the next step, just FYI.