cannot convert from 'ref blah' to 'ref object'

this doesnt compile:

private void changeRef(ref object o)

        {

            o = new GCNotificationStatus();

        }

        private void change(object o)

        {

            o = new GCNotificationStatus();

        }

        protected void Button14_Click(object sender, EventArgs e)

        {

            TaiwanCalendar t = new TaiwanCalendar();

            changeRef(ref t);

            change(t);

        }

the reason