If you've managed to play the first tournament and you only get a crash after it I'm sure we'll be able to figure out what's wrong with the game.
As starters, can you send me the logs created by the game engine:
How to get the logs?
- Go to C:\Users\{username}\AppData\Roaming\Godot\app_userdata\Master of Chess
- In there there is a logs folder
- Open it and copy over the godot.log and the log file with appropriate timestamp