Propulsion System Error

There is something wrong within your propulsion system causing this error.

Diagnosing:

1. Check the propellers for bends, cracks, or damage, and check whether the set screws are loose.
2. Check whether the set screws of the motors are loose, whether the screws of the motor mounts are loose, and check whether the tilt angles of the motors are correct.
3. Check if the locking handle and arm connector bolts are tight. 
4. Check the motors for any possible damages or imperfections.
5. Check that your motor mount is stationary.
   1. If the motor mount is loose it is most common to see it because of a damaged arm. 

Solutions:

1. Restart Aircraft
2. Tighten screws.
3. Replace damaged prop
4. Replace damaged motor.
5. If the motor mount is loose, replace the arm.
6. Downgrade and Reupdate if no damages are found.
7. Replace corresponding ESC.
8. Replace ESC composite cable.
9. Replace aerial electronic module.

Conclusion:

A good look over the arms, motors, and props and the issue can usually be found.