We had a power outage while I was using Lightroom. Now I get his message: Lightroom encountered an error when reading from its preview cache and needs to quit. I uninstalled the software and reinstalled but the problem still exists.
Go to the folder containing your catalog and delete the folder with the extension .lrdata. Then start Lightroom, and it will begin creating a new cache file.
That fixed it. Thanks for your help.
Can you be more specific as to where the file is?
Retrieving data ...