KAMAKAZi666

I know this is an old post, I had the same problem. Tried all the console commands, but nothing helped. I fast traveled to any location, fast traveled back to the castle, walked up to the gate, saved my game, exited Skyrim, and loaded last save, and it immediately went to loading screen, and I was in the castle. Not sure what happened, but I got past it that way....maybe it works for someone else too.

This works. Sorted all my CTD errors, and I can use the HD texture pack now. Thanks mate.