Calender is Disappering

[RahulHawge]

The calendar is disappearing if i update the appcompat library from 'com.android.support:appcompat-v7:21.0.0' to 'com.android.support:appcompat-v7:25.3.1' in gradle file.

Please let me know why is this issue?

[tinhtinhcd]

i found exception throw from this method
private void setDefaultTitleAndMovePage() {
Calendar calendar = Calendar.getInstance();
// The previous is 2 years, the future is 2 years and current year.
int defaultPosition = 12 * 2 + calendar.get(Calendar.MONTH);
mMonthPager.setCurrentItem(defaultPosition, false);
}

after comment the last line, the calendar come but title not update.