Upon opening lightroom classic just today Two things happened. One, all of my files were not found in lightroom, so i had to manually locate them and re-pair them to the photos in the catalog. Two, my user presets completely dissapeared. They are not in my files, user files, anywhere but were working just the day before. Why is this? Even the photos that I edited before are shown in the history tab to have been edited with my presets, but they are still nowhere to be found.
Very strange - Did anything change with your computer yesterday? New OS updates automatic or manual? DId you disconnect any drives? Please tell us what type of computer, the OS you are using and where you keep your photos (originals). That might help figure out what happened.