Suddenly after using Lightroom CC for several months, I cannot open it. I get an error message saying "Lightroom encountered an error when reading from preview cache" and has to close; will fix next time. Many times later, still cannot open it. Anyone else with this problem or how to fix it? Thanks.
I had exactly the same issue and fixed it almost instantly by following the suggestion to rename the previews.lrdata folder in my latest lightroom backup file. This is the same as deleting it. When you then open Lightroom, it will regenerate the missing previews quickly and you will be back in business. My problem was caused by an interruption in the backup process which corrupted the file. John W.