While you troubleshoot your issues with dropbox.com, can you at least put the images up in a couple other locations so we can at least try to download them? Even if it is just Google Drive, OneDrive.
We are migrating all the images to a new location and will have them posted today.
Very sorry about the inconvenience and delays.
The dropbox links are working again. We will be releasing a new version 2.4 next week with a new download page and more reliable connections. Stay tuned.