@Aptmass Sorry for the delay; this is kind of a weird one for me. Just as a test, could you download a player-made save and try to load it? This will distinguish between an issue in creating a new save and one with loading some other process of the game.
Since you have all packs, you could try either of the saves provided in this post:
The player who made them was fixing Isla Paradiso so that it ran better; she provided her saves so that other players could benefit as well.