Coding not been assigned?

I have inserted this script into the FPS controller and I am adjusting any numerical values to my games. I am currently working on the section to do with Crouch but when ever I try to activate this event it says that uncrouchFixRaycastOriginA has not been assigned. Does anyone know how I can solve this? The whole coding is:

using UnityEngine;
using System.Collections;

public class Crouchv3 : MonoBehaviour {

        public float crouchHeightOffset = 0.9f;

        private CharacterMotor charMotor;
        private CharacterController charCont;

        public Transform uncrouchFixRaycastOriginA;
        public Transform uncrouchFixRaycastOriginB;
        public Transform uncrouchFixRaycastOriginC;
        public Transform uncrouchFixRaycastOriginD;

        public float smoothTime = 0.3f;
        private float targetY = 0;
        private float velocityY = 0;

        public static bool canSprint = true;
        public static bool isSprinting = false;
        public static bool crouch = false;
        private bool canStandUp = true;

        public static bool isWalking = false;

	
        void Start () 
        {       
                charMotor = GetComponent<CharacterMotor>();
                charCont = GetComponent<CharacterController>(); 
        }

        void LateUpdate()
        {
            if (Input.GetButtonDown("Crouch") && canStandUp) {
                crouch=true;
                        isWalking=false;
                        isSprinting=false;
                targetY = -crouchHeightOffset;
                charMotor.movement.maxForwardSpeed = 2.75f;
                charMotor.movement.maxBackwardsSpeed = 2.75f;
                charMotor.movement.maxSidewaysSpeed = 2.6f;
                        charCont.center = new Vector3(0, -crouchHeightOffset/2, 0);
                        charCont.height = 1.1f;
            }

            if (!Input.GetButton("Crouch") && canStandUp) {
                crouch=false;
                targetY = 0;
                charMotor.movement.maxForwardSpeed = 193.77f;
                charMotor.movement.maxBackwardsSpeed = 100f;
                charMotor.movement.maxSidewaysSpeed = 100f;
                        charCont.center = Vector3.zero;
                        charCont.height = 2.0f;
    
						if(Input.GetAxis("Vertical") != 0 || Input.GetAxis("Horizontal") != 0)
                        {               
								if(Input.GetButton("Sprint"))
                                {
 										if (canSprint) 
										{
          										if(Input.GetAxis("Vertical") > 0 && Input.GetAxis("Horizontal") == 0 && !crouch)
												{
                    									isWalking = false;
                    									charMotor.movement.maxForwardSpeed = 300f;
														isSprinting = true;
												
												} else isSprinting = false;
										} 
								}
            					
								else if(Input.GetButton("Walk"))
                                {
                                		isSprinting = false;
                                		isWalking = true;
                                		charMotor.movement.maxForwardSpeed = 193.77f;
                                charMotor.movement.maxBackwardsSpeed = 100f;
                                charMotor.movement.maxSidewaysSpeed = 100f;
                                }
                                else if(!crouch)
                                {
                                        isSprinting = false;
                                        isWalking = false;
            							charMotor.movement.maxForwardSpeed = 5.5f;
            charMotor.movement.maxBackwardsSpeed = 5.5f;
            charMotor.movement.maxSidewaysSpeed = 5.35f;
		}
	}
} 
            
		if(Physics.Raycast(uncrouchFixRaycastOriginA.position, Vector3.up, crouchHeightOffset)||Physics.Raycast(uncrouchFixRaycastOriginB.position, Vector3.up, crouchHeightOffset)||Physics.Raycast(uncrouchFixRaycastOriginC.position, Vector3.up, crouchHeightOffset)||Physics.Raycast(uncrouchFixRaycastOriginD.position, Vector3.up, crouchHeightOffset))
			canStandUp=false; else canStandUp=true;


            float newY = Mathf.SmoothDamp(Camera.main.transform.localPosition.y, targetY, ref velocityY, smoothTime);
            Camera.main.transform.localPosition = new Vector3(0, newY, 0);

			charMotor.jumping.enabled = !crouch;
		
        } 
}

This code expects the uncrouchFixRaycastOriginA to be assigned in the inspector, or more remotely possible, by another script. Typically you would drag and drop an game object onto the ‘uncrouchFixRaycastOriginA’ variable. If you are doing this and the script is still failing, check to make sure you don’t have the script attached to more than one game object with ‘uncroucnFixRaycastOriginA’ not assigned in one of the instances.