Oh thank god for you guys. I thought I was going insane here. My particular corruption actually manifested as an inability to save games beyond a certain point -- and this applied to everything. Fast travel, entering buildings, quick-save, regular save. As soon as I tried, boom, instant crash-to-desktop with no error messages of any kind. I found one save from about two days ago that seemed okay (hated the idea of having to replay, but I did anyway). Anyway, within a couple minutes on that save position, crashing again. So instead I skipped where I was, went elsewhere in the world, and although I didn't yet encounter the crash in about 20 minutes of play, but still couldn't quite trust things. I did exactly this -- replacing Skyrim - Interface.bsa and the TESV.exe files with restore-point versions -- and voila, the supposedly broken save games from last night work just fine and no more CTDs. THANK YOU. (On edit: Yep, confirmed it was the patch. I reconnected, did a scan, let Steam patch the game with those two files. Back to CTD on saving. Exit game, re-replace those files with the old versions and no more save-game crashes.)