Lightroom Catalogue shows "0 photos"..

I opened the right catalogue, the same one I worked on last night. I open it today, and it says "0 Photos". I've tried relaunching, and I am defintiley in the right catalogue. I edited 100/500 photos lasdt night and really do not watn to start again. This is NOT a missing file error. Everything is still in the same place on my Harddrive.