wp-simpleviewer “directory does not exist” after plugin upgrade

Hi, I have just upgraded the plugin to version 1.5.3 from v1.1 (I am on WP 2.8.4). I had to update the path address in the settings, but the galleries now display fine in the posts.

However, “Manage WP-SimpleViewer galleries” can’t find the directory. I have configured the addresses in the URL and path fields, but still receive the message “The following directory does not exist – please create it and upload your images to subdirectories of it: https://livingveniceblog.com/wp-content/galleries/”

The directory does exist, has for some time, and has always worked; how I can determine what it’s looking for now?

Thanks very much for any pointers.