I'm having the same issue. Got some vanilla DLC ticked, and no other submods or anything. The game loads up, I pick time to start from, pick the character to play as, and it loads, then ... nothing. It freezes and eventually just goes back to Windows.
'A Game of Thrones' is a user modification for Crusader Kings II not affiliated in anyway with Paradox Interactive or the rights holders to 'Game of Thrones' and 'A Song of Ice and Fire'. This modification and forum takes no income or profit, whether it be through donations, advertisements or any other form of revenue.