Careful using the p-word. That's one-strike-worthy stuff right there. I haven't found a way to get around whatever's happened. I tried every save right back to the first save outside of Helgen - every one CTDs at the cell Karthspire is in. Which I find odd, seeing as I've been to Old Hroldan and Soljund's Sinkhole. Can't fast-travel to them or Karthspire Camp now. And of course, Bethsoft's answer is uninstall, reinstall, wait for the next patch. EDIT: Tinker time: TLL: No - disable LOD, reload cleansave, FTT to Old Hroldan, proceed toward Karthspire cell, CTD COC: No - coc karthspirecamp gets me to the camp, but the moment I get to where I discover Karthspire proper, CTD COC KarthspireCamp + TLL: no coc karthspirereboubtexterior: no coc karthspireredoubtstart (inside of the cave) and walk outside to continue the quest: no above+ setstage + port esbern and delphine in: no, they don't talk about the quest above - setstage: no, they freeze, CTD any of these + TAI (just a wild guess): no Just got the Creation Kit. Dicked around in it for a bit to try and see if I could mod the Karthspire experience so it would work. No dice. Downgrade to 12.1 ATI drivers, upgrade to 21.4 - nope, neither