I get an error msg "LR encountered an error when reading from its preview cache and needs to quit", then an Adobe PS CC window pops up and asks to licence software; Running Windows 8.1; Preview Cahce folder deleted; LR uninstalled, reinstalled. No joy. I have CC membership. Help?
With Lightroom closed, use your system browser to open the folder containing your Lightroom catalog. You will find a folder with the extension .lrdata. It will have the same name as your catalog. You need to delete that folder. Then start Lightroom, and it will generate a new previews folder automatically for you.
OK, solved. Thanks!