BAE146-100 range

Plane, BAE146-100 - 

Route number JV1675 / JV1676 Departure Nice - Côte d'Azur, LFMN (NCE), France

842 NM Destination Belfast - Aldergrove, EGAA (BFS), United Kingdom

I dont get any message on edit route using this plane that range is limited, but if i take look accepted route seats is limited to 77pax Nice - Côte d'Azur (LFMN) - Belfast - Aldergrove (EGAA)

and 82 pax on Belfast - Aldergrove (EGAA) - Nice - Côte d'Azur (LFMN)