I edited the album.config file and could then run default.asp without an error. It now doesn't know about the category1 album I created previously.
I then try to upload to the Default album and I get an error in thumb.aspx. It does upload the image and a .config file but no thumbnail.
If I move back the album.config file that has category1, I get the thumb.aspx error again when running default.aspx. I'm guessing because there were no thumbnails being uploaded.