allright, Ultra is apparantly too much for your PC, try high or make your custom settings again, since ive found something better: Im now running at my own prefered videosettings, the trick is to circumvent Steam, which can be done by executing your 'TESV.exe' (not the launcher) as administrator.
tested it out today and last night havent had a crash in about 10 hours of playtime
warning: You wont get Steam achievements if you play like this.
