Basically the title. I've come out of doing a few quests for Aengoth, when Beauchamp walks up to stand by the Mages Guild. If I go near him, my framerate collapses to zero in a second or two, and then the game crashes. If I run away from where he is, the game carries on, but I've found that if I go towards the silt strider, no matter how far away I try to be from Beauchamp, it still crashes my game. I'm assuming it's him because he's the only change since I was walking past without a problem. It's not specifically looking at him, either, as I've looked down and tried to go past, but no luck.
I've tried 'reinstalling' the Morroblivion core, but it hasn't changed anything - at this point I'd be fine with just deleting him from the game.

http://youtu.be/pvn_r5Neahk
http://youtu.be/pvn_r5Neahk
Clip for Louis Beauchamp. What could be Causing your Problem is Creature in the Ground or Building near Him.
Some where away from Louis but where you can see Him ,,Open ~ type tcm Press Enter will put in Camera Mode go through the Ground in the Area and See if there is a Creature anywhere in Ground or Building,,If you Find 1 Open ~ Click on Critter then Type Disable then Press Enter critter will Disappear. To come out Camera Mode Open ~ Type tcm Press Enter then Try and Go to Louis.
If So Save you Game then Exit and Reload then go to Louis again. see if this Helps.