Your gallery is certainly is Media Library gallery but there appears to be no images attached to the post containing the gallery.
Attaching images to a post is done purely through WordPress's own procedures and is not something unique to WP-SimpleViewer. A gallery created by WP-SimpleViewer simply displays all images attached to the post containing the gallery.
The first set of steps above should work fine (and are relevent to WordPress 4.0).
You say in your original post that "When I try to edit, the 'uploaded to this page' option does not show.".
You should be able to access the 'Uploaded to this post' section by following the second set of steps above.
In each set of steps (to attach images to a post and to check which images have been uploaded to a post), please let me know exactly how far you get, at what point you get stuck and what happens. What do you see (or not see) on screen that seems to be unexpected?
If you continue to experience difficulties, I would certainly be willing to investigate further but I would need access to your WordPress installation and web server. If you are agreeable to this, please let me know and I will send you an email where you can send me your login details.
SimpleViewer Support Team.