I had this problem when I attempt to use my ship as clan-management interface. I went to the ship, left the port of Neketaka, managing the equipments and hairstyles of my clans, then resume my journey in the city, and saved the file. During the clan management session, as I replaced the roster with another batch of clansmen, when I opened the inventory interface, instead of the main character, it showed the last character which I managed in the previous batch of roster and already removed. As I tried loading the file later, I ended up at the main menu, with the same message that haunted everyone in this thread. I let Steam verified the integrity of the game files, and that save file remain unusable. Eventually I loaded an earlier save file, and tried to redo the whole thing. This time, I sent everyone onshore during each session, change their inventory or hairstyles, and most importantly, UPGRADE characters, then sent them back to the ship, and sent another batch onshore. The save file I created after this attempt functions properly. Is it possible that the problem got something to do with the upgrading system? By the way, personally I would suggest a clansmen management interface which is more user-friendly. Just my two cents.
