Worked fine the first time I ran it now it will not load images either by drag and drop or browse.
Make sure that your image filenames use only alpha-numeric characters (and not other characters such as apostrophes or commas).
As the image filenames form part of a URL when uploaded to a web server, it would be wise to use only web-safe characters. Please see section 2.3 of this document for details.
Characters that are allowed in a URI but do not have a reserved purpose are called unreserved. These include uppercase and lowercase letters, decimal digits, hyphen, period, underscore, and tilde.
JuiceboxBuilder-Pro should be able to handle all images whose filenames use any or all of these characters.
Perhaps JuiceboxBuilder-Pro is failing to add a particular image.
If this is the case, then try adding your images in small batches and then one at a time to try to find the image causing the problem.
I uninstalled the lite ver before installing the pro version - don't know if that matters or not.
This does not matter. You can install and run JuiceboxBuilder-Lite and JuiceboxBuilder-Pro side-by-side on the same machine.
If I open a Gallery I have created with SimpleViewer it only loads the first 15 images.
If you continue to experience difficulties, perhaps you could zip the gallery and email it to me (or upload it somewhere and provide a download link) so that I can take a look and help further.