Something is seriously messed up with AI group relations in that savegame.
I tried playing it and indeed, Jean Dusac gets killed. I managed to fix that by putting a line into "quests_reaction.c" to assign him to group "FRANCE_CITIZENS". But Jean Dusac was just the start of the trouble. After talking to him (and to Cecile Bienbonne), I was able to bribe guard Etienne Dupuis to let me into the prison to see Tkixi Pijuan - who is sometimes, but not always, cowering in "afraid" mode so I can't talk to him. If not, I can talk, he's drunk and incoherent, so I retire to the tavern. Next day I return to prison and, if he's not in "afraid" mode, Tkixi (how do you pronounce that?
) tells me about his ship. I'm then supposed to talk again to Etienne Dupuis, but he refuses to start a dialog. Not a blank dialog, but no dialog at all - he just stands there inert. I tried moving him to "FRANCE_SOLDIERS" but all that did was make him consistently go into "afraid" mode, so I still couldn't talk to him. At that point I gave up, not least because if AI group relations are this badly messed up then they'll probably get in the way again later.
The questbook shows that
@Hylie Pistof has done some other quests, but none that have caused any side-effects as far as I know. The only ones which I've almost never done myself are the "fetch" quests and I doubt they're what affected AI group relations. The other difference is that
@Hylie Pistof has installed
@DeathDaisy's music pack, which again is unlikely to do anything to group relations. (The sound associations set up by the music pack must be stored in the savegame because one thing I tried was going to sea, getting clear of Guadeloupe in the hope that would reset local AI groups, then returning. It didn't help, but on the way back into Point a Pitre the background music to sailing was Pachebel's Canon, and normally the only time you should hear that is during Ardent's wedding. There were, of course, also a lot of messages in "system.log" about being unable to find the rest of the music files called for by that pack.)
For comparison, I then loaded up one of my own savegames and blitzed through the "Rescue Peter Blood's Crew" quest, then went straight to Guadeloupe and completed "Search for Peter Blood's Ship" without any similar trouble. So there's nothing inherently wrong with the quest code.