Are you on someone else's internet? I had hosted a file I needed to print on filegarden and tried to log in at the library by me, but the library's firewall blocked the connection. I couldn't load my file even though I had the direct link to the image, but also couldn't connect to filegarden's file list, either, which doesn't sound like it's a problem for you. If you're using public(-ish) wifi, the site might be blacklisted (or not whitelisted). Can you open up the images in a tab by themselves? Like this? Or is there an error, and if so, what is it?
Secondarily, when I was trying to upload some images the other day, the image previews on the file list wasn't loading for me, though the files themselves were fine. It could be temporary outage(s) and might fix itself with time.
If filegarden no longer works for you, you could try some other hosts like those listed on this thread.