I work locally with MAMP (WAMP).
After the images are uploaded in a new gallery, I see the list of images with their Metadata, Title/captions, Author ... but not the thumbnails, there's a question mark instead. (when i click on thumbnail, the big sized image loads, meaning they are in the _gallery folder)
Same when I VIEW the gallery (front end) : question marks...
When clicked, the big sized image won't load this time, just the loader that keeps on turning, and proud Mary that keeps on burning..
Do you have a clue?