Question Maybe a Bug? CustomProprerties

Is working perfectly, but getting this error when i get on slots.
Should i get worries about that?

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using Photon.Pun;
5. using TMPro;
6. using System.IO;
7. using Photon.Realtime;
8. using Hashtable = ExitGames.Client.Photon.Hashtable;
9.  
10. public class SpawnManager : MonoBehaviourPunCallbacks
11. {
12.     public static SpawnManager Instance;
13.     private bool[] isSlotOccuped;
14.  
15.  
16.     public Transform[] slots;
17.     public GameObject[] slotsButtons;
18.     public GameObject questionMenuButton;
19.     public GameObject questionMenu;
20.     public int slotsActual;
21.     public int ready = 0;
22.     public bool startQuestionTrigger = true;
23.  
24.     public void Awake()
25.     {
26.         if(SpawnManager.Instance == null)
27.         {
28.             SpawnManager.Instance = this;
29.         }
30.     }
31.     public void Start()
32.     {
33.         isSlotOccuped = new bool[PhotonNetwork.PlayerList.Length];
34.         ChangeSizeSlots();
35.     }
36.     public void ChangeSizeSlots()
37.     {
38.  
39.         slotsActual = PhotonNetwork.PlayerList.Length;
40.  
41.         for (int i = 0; i < slotsActual; i++)
42.         {
43.             slotsButtons[i].SetActive(true);
44.             isSlotOccuped[i] = false;
45.  
46.         }
47.  
48.     }
49.  
50.     void TakeSlot(int slotIndex)
51.     {
52.         if(isSlotOccuped[slotIndex] == false)
53.         {
54.             PhotonNetwork.Instantiate(Path.Combine("PhotonPrefabs", "Player"), SpawnManager.Instance.slots[slotIndex].position, Quaternion.identity);  
55.         }
56.         else
57.         {
58.             Debug.Log("Slot Occuped");
59.         }    
60.         PhotonNetwork.CurrentRoom.SetCustomProperties(new Hashtable() { { "Slot", slotIndex } });
61.         isSlotOccuped[slotIndex] = true;      
62.     }
63.  
64.     public override void OnRoomPropertiesUpdate(Hashtable propertisThatChanged)
65.     {
66.  
67.         VerifySlot();
68.         VeifyStartQuestion();
69.  
70.     }
71.  
72.  
73.     void VerifySlot()
74.     {
75.         slotsButtons[(int)PhotonNetwork.CurrentRoom.CustomProperties["Slot"]].SetActive(false);
76.         ready++;
77.         if(ready == slotsActual)
78.         {
79.             questionMenuButton.SetActive(PhotonNetwork.IsMasterClient);
80.         }
81.      
82.     }
83.     public void StartQuestion(bool startIndex)
84.     {
85.         PhotonNetwork.CurrentRoom.SetCustomProperties(new Hashtable() { { "StartQuestion", startIndex } });
86.      
87.     }
88.     public void VeifyStartQuestion()
89.     {
90.      
91.         if(startQuestionTrigger == (bool)PhotonNetwork.CurrentRoom.CustomProperties["StartQuestion"])
92.         {
93.             OpenQuestionMenu();
94.         }
95.     }
96.  
97.     void OpenQuestionMenu()
98.     {
99.         questionMenu.SetActive(true);
100.         PhotonNetwork.CurrentRoom.SetCustomProperties(new Hashtable() { { "StartQuestion", false } });
101.     }
102.  
103.  
104.  
105. }
106.