Can't change objects layer through script

I'm currently working on a pickup mechanic for my fps game, but when I test it in play mode, I get an error:
A game object can only be in one layer. The layer needs to be in the range [0...31]
UnityEngine.StackTraceUtility:ExtractStackTrace ().

My guess is that the unity engine thinks I'm trying to set the gun to multiple layers at a time.
Here is my code:

Code (CSharp):

1.  
2. [SerializeField] Camera cam;
3.     [SerializeField] Transform weaponPos;
4.     [SerializeField] LayerMask InteractableLayer;
5.     [SerializeField] LayerMask weaponLayer;
6.  
7.     public float grabDistance;
8.     public float throwForce = 6f;
9.  
10.     GameObject weapon;
11.  
12.     Rigidbody rb;
13.  
14.     void Update()
15.     {
16.         if (Input.GetKeyDown(KeyCode.E))
17.         {
18.             RaycastHit hit;
19.             if (Physics.Raycast(cam.transform.position, cam.transform.forward, out hit, grabDistance, InteractableLayer))
20.             {
21.                 rb = hit.transform.GetComponent<Rigidbody>();
22.  
23.                 if (rb != null)
24.                 {
25.                     rb.useGravity = false;
26.                     weapon = hit.transform.gameObject;
27.                     currentLayer = weaponLayer;
28.                     weapon.transform.position = weaponPos.position;
29.                     weapon.transform.parent = weaponPos.transform;
30.                 }
31.             }
32.         }
33.         else if (Input.GetKeyDown(KeyCode.Q))
34.         {
35.             if (weapon != null)
36.             {
37.                 rb.useGravity = true;
38.                 rb.AddForce(cam.transform.forward * throwForce, ForceMode.Impulse);
39.                 currentLayer = InteractableLayer;
40.                 weapon.transform.parent = null;
41.                 rb = null;
42.                 weapon = null;
43.             }
44.         }
45.     }

Is there any way I might be able to fix this?

 

Layers vs Masks:

https://forum.unity.com/threads/raycast-layermask-parameter.944194/#post-6161542

 

This helped so much!
Thanks heaps!

 

probably you are trying to acces layer is not exist.Or the codes you are trying to change layers executed same time.Try to delete one of them then try again if it works then codes get executed same time

Code (CSharp):

1.  gameObject.layer = LayerMask.NameToLayer("thelayeryouwanttochange");
2.  
3. try this maybe it will work.