After 3 hours of play (and rather good ones) I decided to continue on with the "Alduin's Wall" quest. As I made my way to Karthspire, the dragon that ALWAYS appears during the quest attacked me. However, I wasn't alone. A Thalmor escort were the first ones to be attacked and I was traveling with Lydia. I managed to cross the bridge when I spotted Esbern, summoning a Fire Atronach. This is when it crashed. Well, RIGHT when the Atronach cast a fire spell at the Blood Dragon.
Now... I have no idea as to why it crashed. Was it because of all the action or spending 3-4 hours on the game?