hp indigo press 3050 Exit rotors are not ready for print.....

Hi, I'm new
getting this error anyone got a idea
<V6.4.2.i8/1360> Exit rotors are not ready for print, try printing again, if fails check:
1. Functionality of output rotor position sensor.
2. Synchronization between rotors and machine.
3. Sensor flag adjustment.

 

check that there is no paper stuck in the perfector area as well as in the exit rotors area and that the suction cups are in place

 

is the drive belt for the exit rotors intact ?

 

Thanks
problem solved
the machine was not synchronized