from Thierry:
the real place for the concert in caen in 1989 was 'hall des expositions' a smallest venue
Certainly due to poor sales
I'm sure because i was in this concert
from Richard S.:
If the concert was played in the Hall des Expositions and not in the inner courtyard of Caen Castle, it was not because ticket sales were poor but because of the forecast of thunderstorms and rain on the evening of the concert. The courtyard being naturally outside, this was the solution found