If you look through the archives here and on the other support sites, you will find that this problem has been around for years and is fairly widespread. So far, the people at Bethesda have done nothing to fix it. It started doing it to me a few days ago. When you try to go into the magic menu, it CTDs. I have seen a LOT of people try a LOT of things and nothing seems to work except starting a new game and wiping out all of your old saves. Although some people have gotten lucky and fixed it by removing and then relearning spells. What really ticks me off is the complete lack of interest the program authors seem to have in fixing a MAJOR gamebreaker. The game can be unstable enough without this stuff happening every time you need to change spells. For me, I only noticed it when I went to change my shout to the Vampire form spell. I have no idea when it actually broke because I had not changed spells in almost 900 saves. It's very frustrating when you see a lot of posts from users having the same major problem and absolutely no help from the designers. I guess that once they have your money, they just don't care. My Daughter tells me they are working on an Elder Scrolls 6. Here is a novel idea for Bethesda... How about fixing thee overpriced mess that is Skyrim, before making a new overpriced bug pile. As for me, I finally gave up, wiped my saves, and started a new game from scratch. There goes hundreds of hours playtime, but it was my only remaining option. Now I am having new fun and games, with it CTDing as soon as I enter the first town at the beginning of the game.