Couldnt make a flight reward booking

Tried to make an Aeroplan flight reservation. Found a set of flights, provided all the information needed to make the reservation but accept and submit button never enabled. No indication of what was missing.
Gave up and tried to book same flights via Aeroplan web site. Had to wait about 30 minutes before the business class seats were released from my previous attempt.

NormTO about Aeroplan, v4.3