In a newly published game (android) that utilises a remote database to get data, I get daily many app crashes reports that I cannot reproduce or i have not encountered in my tests over several real devices and virtual devices. The top crash report is:
java.lang.RuntimeException: 
 at android.app.ActivityThread.performLaunchActivity 
  (ActivityThread.java:2805)
 at android.app.ActivityThread.handleLaunchActivity 
(ActivityThread.java:2883)
 at android.app.ActivityThread.-wrap11 (Unknown Source)
 at android.app.ActivityThread$H.handleMessage (ActivityThread.java:1613)
 at android.os.Handler.dispatchMessage (Handler.java:106)
 at android.os.Looper.loop (Looper.java:164)
 at android.app.ActivityThread.main (ActivityThread.java:6523)
 at java.lang.reflect.Method.invoke (Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run 
(RuntimeInit.java:438)
  at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:857)
Caused by: java.lang.NullPointerException: 
  at com.my.app.activity.LevelActivity.onCreate (LevelActivity.java:82)
  at android.app.Activity.performCreate (Activity.java:7023)
  at android.app.Activity.performCreate (Activity.java:7014)
   at android.app.Instrumentation.callActivityOnCreate 
(Instrumentation.java:1214)
  at android.app.ActivityThread.performLaunchActivity 
(ActivityThread.java:2758)
for example the LevelActivity.java:82 :
        levelNo = MainActivity.dbHelper.GetLevelById(Constant.CATE_ID, Constant.SUB_CAT_ID);
and the oncreate until line with the NPE:
 public void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_level);
    Utils.transparentStatusAndNavigation(LevelActivity.this);
    layout = findViewById(R.id.layout);
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        layout.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LIGHT_STATUS_BAR);
    }
    toolbar = findViewById(R.id.toolBar);
    setSupportActionBar(toolbar);
    getSupportActionBar().setTitle(R.string.select_level);
    toolbar.setNavigationOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            onBackPressed();
        }
    });
    recyclerView.setLayoutManager(new LinearLayoutManager(LevelActivity.this));
    levelNo = MainActivity.dbHelper.GetLevelById(Constant.CATE_ID, Constant.SUB_CAT_ID);
i don't know where to begin since I have never encountered this error or similar crash
All crashes related to this app are: java.lang.NullPointerException
this is not a duplicate question as the methods described in the proposed original question do not apply here.
I cannot reproduce the error, how can I debug?
Not all headaches can dissapear with aspirin
