I've been using Lightroom 5.6 for over a year. Today I opened lightroom and was asked to register. Once I was in my catalog all the photos and presets I have uploaded for the past year are gone. What happened?
Moving this discussion to the Photoshop Lightroom forum.
It sounds as if you have created a new catalog. In Lightroom, go to File->Open Recent, and if there is another catalog listed choose it and see what happens.