something changed between the date of your savedgame and 1615,

one of the AI players made a different decision and the "crash event" no longer occurs.

It is not something the player does, it is something the AI does,

It could be one of several things
has something to do with the AI having cheats permanently enabled. (and we cannot turn them off)

or the AI is doing something that breaks the database.

MAYBE it even has something to do with an AI Daimyo sallying? (as puzz recently found when the General that will lead the battle sally's from a castle the games internal default map gets used )


As soon as you can see most of the map the odds of a crash go way up,
(crashes happen far more often)
having ships everywhere, or having matteosartori on.

cheers
B.