It's probably your mods, you have to move your mods out of your mod folder and test if you can start the game.
Start with script mods or other mods that you might have that changes the game a lot, move them outside of the mod folder and see if you can start the game, if you can't, keep moving mods from the folder until you can start the game. When you can start the game, add mods back in until you have found the ones that causes the issue.
Last patch required a lot of old mods to be updated.