Network object manipulation problem

[contac]

I generated two player preforms over the network.When the first player joins, everything will be fine.When the second player joins, it won't be able to operate,
But the first player is still normal,I used SetCharacterMovementInput to realize mobile player ,The following error occurs

NullReferenceException: Object reference not set to an instance of an object
Opsive.UltimateCharacterController.ThirdPersonController.Character.MovementTypes.Combat.GetDeltaYawRotation (System.Single characterHorizontalMovement, System.Single characterForwardMovement, System.Single cameraHorizontalMovement, System.Single cameraVerticalMovement) (at Assets/Opsive/UltimateCharacterController/Scripts/ThirdPersonController/Character/MovementTypes/Combat.cs:28)
Opsive.UltimateCharacterController.Character.UltimateCharacterLocomotionHandler.GetDeltaYawRotation () (at Assets/Opsive/UltimateCharacterController/Scripts/Character/UltimateCharacterLocomotionHandler.cs:199)
Opsive.UltimateCharacterController.Game.KinematicObjectManager+KinematicCharacter.FixedMove (System.Boolean manualMove) (at Assets/Opsive/UltimateCharacterController/Scripts/Game/KinematicObjectManager.cs:168)
Opsive.UltimateCharacterController.Game.KinematicObjectManager.FixedUpdate () (at Assets/Opsive/UltimateCharacterController/Scripts/Game/KinematicObjectManager.cs:578)

 

[contac]

I solved this problem by adding the LocalLookSource component to my network prefab ,Start this component when a local player is detected.
I don't know if it's the right solution, but it works ,But Synchronous coordinate is still a problem, but this is probably a completely new problem, and I will try to solve it.