Logcat

09-20 01:45:13.898 15884-15884/? W/will.counterap: JIT profile information will not be recorded: profile file does not exits.
09-20 01:45:13.900 15884-15884/? W/will.counterap: JIT profile information will not be recorded: profile file does not exits.
09-20 01:45:13.991 15884-15884/? W/will.counterap: Accessing hidden method Landroid/view/View;->computeFitSystemWindows(Landroid/graphics/Rect;Landroid/graphics/Rect;)Z (light greylist, reflection)
    Accessing hidden method Landroid/view/ViewGroup;->makeOptionalFitsSystemWindows()V (light greylist, reflection)
09-20 01:45:18.352 15884-15884/com.example.will.counterapp E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.will.counterapp, PID: 15884
    java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
        at com.example.will.counterapp.Counter.createSubButton(Counter.java:112)
        at com.example.will.counterapp.Counter.createCounter(Counter.java:71)
        at com.example.will.counterapp.MainActivity$1.onClick(MainActivity.java:41)
        at android.view.View.performClick(View.java:6597)
        at android.view.View.performClickInternal(View.java:6574)
        at android.view.View.access$3100(View.java:778)
        at android.view.View$PerformClick.run(View.java:25885)
        at android.os.Handler.handleCallback(Handler.java:873)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:193)
        at android.app.ActivityThread.main(ActivityThread.java:6669)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)