NullReferenceException:"Object reference not set to an instance object"

Hello everyone, I´m new in unity 3d so I was making a very very fps(Thanks to ETeeskiTutorials). So I attach a "MouseLookScript" to the main camera and It´s work. Well, then I create a capsule and I use it as "PlayerCapsule". Next I Attach the main camera to the PlayerCapsule so the main camera follow the "player". Well, when i want to test the "game"xD Its says NullReferenceException:"Object reference not set to an instance object"

I dont know what is happening, here i give us the scripts that i use:

MouseLookScript:

 var LookSensitivity : float = 5;
 @HideInInspector
 var yRotation : float;
 @HideInInspector
 var xRotation : float;
 @HideInInspector
 var currentYRotation : float;
 @HideInInspector
 var currentXRotation : float;
 @HideInInspector
 var yRotationV : float;
 @HideInInspector
 var xRotationV : float;
 var LookSmoothDump : float = 0.1;
 
 function Update () 
 {
     yRotation += Input.GetAxis("Mouse X") * LookSensitivity;
     xRotation -= Input.GetAxis("Mouse Y") * LookSensitivity;
     
     xRotation = Mathf.Clamp(xRotation, -90, 90);
     
     currentXRotation = Mathf.SmoothDamp(currentXRotation, xRotation, xRotationV, LookSmoothDump);
     currentYRotation = Mathf.SmoothDamp(currentYRotation, yRotation, yRotationV, LookSmoothDump);
     
     transform.rotation = Quaternion.Euler(currentXRotation, currentYRotation, 0);
 }

PlayerMovementScript:

var walkAcceleration : float = 5;

var cameraObject : GameObject;

 function Update () 
 {
     transform.rotation = Quaternion.Euler(0, cameraObject.GetComponent(MouseLookScript).currentyRotation, 0);
     rigidbody.AddRelativeForce(Input.GetAxis("Horizontal") * walkAcceleration, 0, Input.GetAxis("Vertical") * walkAcceleration);
 }