I want to help you. I fixed this issue today.
If you look icons path it will see like that
<img src="/shutter_reloaded/images/close.gif" title="Close"
you should change path. You should give full path example:
<img src="https://rabiaaydogan.com/wp-content/plugins/nextgen-gallery/products/photocrati_nextgen/modules/lightbox/static/shutter_reloaded/images/close.gif" title="Close">
How can you change path? I’ll give you answers, step by step
1.Follow this way “/www/wp-content/plugins/nextgen-gallery/products/photocrati_nextgen/modules/lightbox/static/shutter_reloaded”
2.Open shutter.js with notepad
3.Look 24 row. There is a “var imagePath = nextgen_lightbox_settings.static_path + ‘/shutter_reloaded/images/’;
4. Replace it like this “https://rabiaaydogan.com/wp-content/plugins/nextgen-gallery/products/photocrati_nextgen/modules/lightbox/static/shutter_reloaded/images/”
5. Finally icons will show ??
Sorry for my english ?? i am trying to learn english.
Have a nice day!
