Motor test , stop all motors is not working

CUBE ORANGE , ARDUPLANE 4.5.7 , MP 1.3.83 , Q_FRAME_CLASS: Frame Class=4 , Q_FRAME_TYPE: Frame Type=3 , 8 MOTORS ARE CONNECTED TO MAIN 1-8 OUT , START MOTOR TEST FOR MOTOR A,B,C ….. IS WORKING , STOP ALL MOTOR IS NOT WORKING , A MESSAGE ON MP “Command was rejected” .