NullPointerException

[Maxxan]

I tried to use the code from the sample app, but it fails to show the dialog and crashes with a null pointer exception.

Here is the part of the library that fails. (MonthPickerView) view.findViewById(R.id.monthPicker) returns null. I've tried to clean the project, but the same problem. Any idea what could cause this?

        view = inflater.inflate(R.layout.month_picker_dialog, null);

        setView(view);
        _monthPicker = (MonthPickerView) view.findViewById(R.id.monthPicker);
        _monthPicker.setOnDateListener(new MonthPickerView.OnDateSet() {
            @Override
            public void onDateSet() {
                tryNotifyDateSet();
                MonthPickerDialog.this.dismiss();
            }
        });