Having an Error with An Enum : error CS0176: Static member `BossOne.BossActionType.Attacking' cannot be accessed with an instance reference, qualify it with a type name instead

Skip to third point for Solution. The rest explains other problems you are going to encounter.

Within C# you can have more than one variable with the same name, if the new variable is nested within a loop or a function. So the problem is with these lines:

 void OnTriggerEnter (Collider other){
          if (other.gameObject.tag == "Player") {
              BossActionType BossStances = BossStance.Aleted;
  
       }
 }
  
  
 void OnTriggerExit (Collider other){
        if (other.gameObject.tag == "Player") {
              BossActionType BossStances  =    BossStance.Dorment;
  
          }
 }
 

Each time a check is done you create a new variable called BossStances . And as soon as you leave the If function that checks for the tag that variable is lost. So simply write:

 void OnTriggerEnter (Collider other){
          if (other.gameObject.tag == "Player") {
              BossStance = BossStance.Aleted;
  
       }
 }     
  
 void OnTriggerExit (Collider other){
        if (other.gameObject.tag == "Player") {
              BossStance  =    BossStance.Dorment;
  
          }
 }

Secondly not sure why you are creating a new variable BossStance( s ). These variables just get destroyed and never used again with each check.

Lastly, you never assign an Stance to your BossStance variable, so add the following:

 void Start () {
     BossStance = BossActionType.Dorment;
 }

Hi, thanks for the Input. Missed the START function to set the start Stance of the Boss, I have Already tried BossStance = BossStance.Attacking; that was the first thing I tried and I got

error CS0176: Static member `BossOne.BossActionType.Attacking' cannot be accessed with an instance reference, qualify it with a type name instead

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class BossOne : MonoBehaviour {
 
     public GameObject UfoGun1;
     public GameObject UfoGun2;
     public GameObject UfoGun3;
 
     public GameObject gunStartPos;
 
     public GameObject gunAttackPos1;
     public GameObject gunAttackPos2;
     public GameObject gunAttackPos3;
 
     public Material GunClosed;
     public Material GunOpen;
 
     public Material GunToChange1;
     public Material GunToChange2;
     public Material GunToChange3;
 
 
     public bool WeekpointActive;
 
     public enum BossActionType
     {
         Aleted,
         Dorment,
         Attacking
     }
 
     public BossActionType BossStance;
 
 
 
     // Use this for initialization
     void Start () {
         GunToChange1 = GunClosed;
         GunToChange2 = GunClosed;
         GunToChange3 = GunClosed;
         BossStance = BossActionType.Dorment;
     }
     
     // Update is called once per frame
     void Update () {
         switch (BossStance)
         {
         case BossActionType.Dorment:
             HandleDormentState ();
             break;
 
         case BossActionType.Aleted:
             HandleAletedState ();
             break;
 
         case BossActionType.Attacking:
             HandleAttackingState ();
             break;
 
 
 
         }
     }
 
 
     void HandleDormentState(){
         UfoGun1.transform.position = gunStartPos.transform.position; // LERP
         UfoGun2.transform.position = gunStartPos.transform.position; // LERP
         UfoGun3.transform.position = gunStartPos.transform.position;
     }
 
     void HandleAletedState(){
         UfoGun1.transform.position = gunAttackPos1.transform.position; // LERP
         UfoGun2.transform.position = gunAttackPos2.transform.position; // LERP
         UfoGun3.transform.position = gunAttackPos3.transform.position; // LERP
         StartCoroutine(WaitforAttack());
 
     }
 
     void HandleAttackingState() {
         StartCoroutine(AttackGun1());
     }
 
     IEnumerator WaitforAttack (){
         yield return new WaitForSeconds (3.0f);
         BossStance = BossStance.Attacking;
     }
 
     IEnumerator AttackGun1(){
         GunToChange1  = GunOpen;
         WeekpointActive = true;
         yield return new WaitForSeconds (3.0f);
 
         GunToChange1  = GunClosed;
         WeekpointActive = false;
         yield return new WaitForSeconds (1.0f);
         StartCoroutine(AttackGun2());
 
     }
 
     IEnumerator AttackGun2(){
         GunToChange2  = GunOpen;
         WeekpointActive = true;
         yield return new WaitForSeconds (3.0f);
 
         GunToChange2  = GunClosed;
         WeekpointActive = false;
         yield return new WaitForSeconds (1.0f);
         StartCoroutine(AttackGun3());
 
     }
 
     IEnumerator AttackGun3(){
         GunToChange3  = GunOpen;
         WeekpointActive = true;
         yield return new WaitForSeconds (3.0f);
 
         GunToChange3  = GunClosed;
         WeekpointActive = false;
         yield return new WaitForSeconds (1.0f);
         StartCoroutine(AttackGun1());
 
     }
         
 
 
 
 
     void OnTriggerEnter (Collider other){
         if (other.gameObject.tag == "Player") {
             BossStance = BossStance.Aleted;
 
         }
     }
 
 
     void OnTriggerExit (Collider other){
         if (other.gameObject.tag == "Player") {
             BossStance  =    BossStance.Dorment;
 
         }
     }
 
 
 
 }