Upload & Sell: Off
So if any of you helpful folks are still following this thread, guess what? Now I'm seeing some of my previously downloaded raw files (i.e. 2 or 3 years old) being rendered in the same strange way. This has happened with 2 files so far. In one case, switching the process version to 2010 restored the image. In the other case, no dice. And in the second case, the file at first appeared corrupted only in the develop module - switching to library or grid view showed a normal preview - but eventually the previews were screwed up too. So...Show more →
Could be bad RAM, or a glitch in the OS, or in Lightroom.
I hope you have backups of all your files. If not, yank the hard drive and make a backup using another computer ASAP. If you make the backup using your possibly-defective computer, then your new backup will possibly be defective, which defeats the purpose of a backup.