Bug Function Somtime works somtimes not

Good day,
i develop a game for mobile.
I have a shop etc. where you can buy stuff, but this feature sometimes doesn't work. (On PC it always works) I have attached a script example at the bottom of the appendix.
thanks in advance.

Code (CSharp):

1. //Buy- Manager
2.  
3.     public void itemKaufen1(int itemPreis)
4.     {
5.         if(kontoStandt >= itemPreis)
6.         {
7.             kontoStandt = kontoStandt - itemPreis;
8.             //In klammern wie viel du von diesem Object bekommst;.
9.             myInventar.ChangeItem1(1);
10.             item1istGekauft = 1;
11.             SaveManager.instance.item1istGekauft = item1istGekauft;
12.             SaveManager.instance.item1 = myInventar.item1;
13.             SaveManager.instance.Save();
14.         }
15.  
16.         if(kontoStandt <= itemPreis)
17.         {
18.             Debug.Log("Dont Work");
19.         }
20.         //Kontostandt überprüfen;
21.     }
22.  
23.  
24. //Save Manager
25.  
26.     public static SaveManager instance { get; private set; }//r
27.  
28.     //Data to Save
29.     public int LevelBuyed;
30.     public bool Character01isbuyed;
31.     public int WhichLevel;
32.     public int money;
33.     public int item1istGekauft;
34.     public int item1;//r
35.  
36.  
37.     //Start usw.
38.     private void Awake()
39.     {
40.         if (instance != null && instance != this)//r
41.             Destroy(gameObject);//r
42.         else//r
43.         instance = this;//r
44.         DontDestroyOnLoad(gameObject);//r
45.         Load();//r
46.     }
47.  
48.     //Funktionen
49.     public void Load()//r
50.     {
51.         if(File.Exists(Application.persistentDataPath + "/PlayerInfo.dat"))//r
52.         {
53.             BinaryFormatter bf = new BinaryFormatter();//r
54.             FileStream file = File.Open(Application.persistentDataPath + "/PlayerInfo.dat", FileMode.Open);//r
55.             PlayerData_Storage data = (PlayerData_Storage)bf.Deserialize(file);//r
56.  
57.             LevelBuyed = data.LevelBuyed;
58.             Character01isbuyed = data.Character01isbuyed;
59.             WhichLevel = data.WhichLevel;
60.             money = data.money;
61.             item1istGekauft = data.item1istGekauft;
62.             item1 = data.item1;//r
63.  
64.             file.Close();//r
65.  
66.         }
67.  
68.     }
69.  
70.     public void Save()
71.     {
72.         BinaryFormatter bf = new BinaryFormatter();//r
73.         FileStream file = File.Create(Application.persistentDataPath + "/PlayerInfo.dat");//r
74.         PlayerData_Storage data = new PlayerData_Storage();//r
75.  
76.         data.LevelBuyed = LevelBuyed;
77.         data.Character01isbuyed = Character01isbuyed;
78.         data.WhichLevel = WhichLevel;
79.         data.money = money;
80.         data.item1istGekauft = item1istGekauft;
81.         data.item1 = item1;//r
82.  
83.         bf.Serialize(file, data);//r
84.         file.Close();//r
85.     }
86. }
87.  
88. //Neue Classe
89. [Serializable] //r
90. class PlayerData_Storage //r
91. {
92.     public int LevelBuyed;
93.     public int WhichLevel;
94.     public bool Character01isbuyed;
95.     public int money;
96.     public int item1istGekauft;
97.     public int item1;//R
98. }

 

In what way does it not work?

 

The Button where white and the function does not work.

 

anything in device log? (if its android)
https://answers.unity.com/questions/492681/how-to-use-adb-logcat.html#answer-571021

 

Thanks for awnser, yeah i am on Android, how i show in device log?

 

can call that from commandline (or from the folder where adb.exe is located)

Code (Boo):

1.  adb logcat -s Unity ActivityManager PackageManager dalvikvm DEBUG

or could try unity editor package,
https://docs.unity3d.com/Packages/com.unity.mobile.android-logcat@1.2/manual/index.html

 

I tryed and it only said:

 

there should be hundreds of lines, and it keeps printing more,
and can see debug logs, errors there:

 

Ok, but there is no error and nothing else i dont no how to solve this problem.