14 days ago - Arakrates - Direct link
Heya Sirclive, I am sorry to hear you are currently experiencing problems with launching the game.
In order to best help you, I'll need a couple of more details regarding the crash.

Inside the folder "Documents\Paradox Interactive\Crusader Kings III\crashes" there should be a folder created that contains logs from the crash (debug.log, error.log, game.log & system.log). Could you update the thread with your logs?

In addition, please reinstall the game and make sure all mods are turned off to make sure they aren't interfering with the launch of the game. As with any updates, you may have to wait until your mod author has updated their mods before you can use them.  
14 days ago - Arakrates - Direct link
Glad to hear that it's working again! Have a fantastic day! :D