Hi! Thanks for reporting the crash.
Unfortunately, the save game is unsupported since it was made before 3.0 and resumed past 3.0.
The core issue is that before 3.0, the desert of Kyzul-Kum(east of the Aral Sea) was a normal province but after 3.0 it is a wasteland.
In your save, there is a character that owns that wasteland (characters should never own wastelands) and this character is also a dejoure vassal of one of the crusade participants.
This causes issues when attempting to resolve the crusade. On top of this there are also some other issues that I happened to spot that are direct effects of the wasteland having an owner, so even if you got past this crash, there would likely be more waiting down the line (There is for example a monastery in that wasteland as well).
So the save game was actually broken before this update, you were just lucky up until now, that having an owned wasteland hadn't already caused a crash
Unfortunately, the save game is unsupported since it was made before 3.0 and resumed past 3.0.
The core issue is that before 3.0, the desert of Kyzul-Kum(east of the Aral Sea) was a normal province but after 3.0 it is a wasteland.
In your save, there is a character that owns that wasteland (characters should never own wastelands) and this character is also a dejoure vassal of one of the crusade participants.
This causes issues when attempting to resolve the crusade. On top of this there are also some other issues that I happened to spot that are direct effects of the wasteland having an owner, so even if you got past this crash, there would likely be more waiting down the line (There is for example a monastery in that wasteland as well).
So the save game was actually broken before this update, you were just lucky up until now, that having an owned wasteland hadn't already caused a crash