I would suggest to please go to the location where your catalog is saved, in the same location you will see a folder Lightroom Catalog Previews.lrdata
Please delete the Previews.lrdata folder and then launch Lighroom.
Please let us know if it helps.
As I said originally, I have removed/deleted that folder many times. It rebuilds and then I get the same message. I have also deleted the Preferences folder which is in the same folder as the Presets are in. Neither of these actions work.
I would suggest you to then to please uninstall and reinstall Lr 5.7 on the computer.