Android Question Button Navigation Error While Running

** Activity (main) Pause, UserClosed = false **
*** Service (starter) Create ***
** Service (starter) Start **
** Activity (main) Create, isFirst = true **
main_activity_create (java line: 340)
java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
    at anywheresoftware.b4a.keywords.LayoutBuilder.loadLayout(LayoutBuilder.java:170)
    at anywheresoftware.b4a.objects.ActivityWrapper.LoadLayout(ActivityWrapper.java:209)
    at b4a.example.BottomNavigation.main._activity_create(main.java:340)
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:186)
    at b4a.example.BottomNavigation.main.afterFirstLayout(main.java:104)
    at b4a.example.BottomNavigation.main.access$000(main.java:17)
    at b4a.example.BottomNavigation.main$WaitForLayout.run(main.java:82)
    at android.os.Handler.handleCallback(Handler.java:790)
    at android.os.Handler.dispatchMessage(Handler.java:99)