Your https://www.countyfairgrounds.net/colorado/config.xml file still contains only 14 image entries.
Either:
(1) The 'config.xml' file is not being overwritten in your gallery folder when you edit the gallery with JuiceboxBuilder-Pro.
... or:
(2) The 'config.xml' file is not being overwritten on your web server.
Double-check that your new 'config.xml' file contains 15 image entries (you can open the file in a plain text editor).
If it contains only 14 image entries, then the file is not being overwritten. Check that your gallery folder is not read-only and that you do not have any gallery files open in any applications (other than JuiceboxBuilder-Pro) when you save the gallery on the 'Publish' tab. You could also try saving the new version of the gallery to a completely different folder.
If you are in any doubt that the old 'config.xml' file is being overwritten on your web server, delete it first before uploading the new version in its place.
Also, be sure to upload the new image and thumbnail to the gallery's 'images' and 'thumbs' folders.
After editing a gallery with JuiceboxBuilder-Pro, you should be able to just upload the entire gallery folder to your web server without having to manually pick out any specific files.
If you use a dedicated FTP program such as Filezilla, you could upload the entire gallery folder to your web server (to replace the old version) in a single drag-and-drop action and configure the FTP program to upload only new or updated files (to avoid having to re-upload images that already exist on the server).