XnView Software

I am trying to look at images that are all in one folder. When I open one in xnview mp viewer, I can't move to the next or previous file. If I switch to the browser I can see them all, but even if i open them from the browser I can't scroll in the viewer. Most of these files are not standard image formats, some have no file extension, but I can see them in the browser, and they open normally individually, I just can't scroll through the images in the viewer. How do I fix this?

How are you scrolling?

In Tools > Settings... > Interface there are options to scroll using the mouse and/or keyboard.

check Settings > View > Filter