Help! All my catalogs disappeared when I was backing up one of the catalogs to an external hard drive

I was backing up a large catalog in Elements 13 to an external hard drive. It took longer than usual, and I went away from the computer for a while. When I got back, the computer screen was blank. I had to turn off the computer and then turn it on again for the screen to show up again, and when I opened Elements 13 all 8 of my catalogs were gone. And almost all the options (like manage and restore catalogs) were grayed out. Is there any way to get those catalogs back without uninstalling and reinstalling the program and then restoring all the catalogs from an external hard drive???