I have the same issue : blank page in NextGen gallery settings & other settings.
My wordpress is executed locally, with MAMP, on localhost:8888
The issue comes from the port 8888, seems to not be correctly handled by NextGen.
When I try to display the gallery settings page, I got a lot of “404 not found” on css and js ressources. The port is missing into the ressource url.
The root page is ok (http 200) :
https://localhost:8888/test/wp/wp-admin/admin.php?page=ngg_display_settings
Then the css file is failing, because the port is missing :
https://localhost/test/wp/wp-content/plugins/nextgen-gallery/products/photocrati_nextgen/modules/nextgen_gallery_display/static/nextgen_gallery_related_images.css?ver=3.6.1
