Some images couldn't be added in responsive image gallery

Q: I have been loading image into the window without any problem until I came to one folder of images I cannot load the first 12 images in the folder the others load fine. I even went to copy the folder in different locations but the same thing happens every time. I have been able to load 242 image but not those 12. Any thoughts on what may be happening.

A: Try to drag and drop these images directly to Visual Lightbox window.
You can also send us several pictures, so we can check them.