Testing the script on your site and there is the same problem.
After uploading a new images and remove the first one there is a red cross.
So I'am now sure that this isn't a server isue add my site but in the script.
Please give a solution for this problem.
See attachment it is taken from your site (admin demo)

Dear Anton,

Please give us a link (to [email protected]) to your site and temporary admin user account, and we will try to find out the problem as soon as possible.

Best regards
Web-Dorado team

I don't know why you ask for a temporary admin user account on my site.
As you can see it is also not working on your site.
Please test it on your site and replace the image for a differend one.
You can see that the script isn't working correct.
So in my opion there must be a update from the script and not only when users wrote a topic that there is a error on the same isue as other users also report.

Dear Anton,

We asked for admin access to see what's the problem in your site, because here we don't see any problems in image loading on our site.

Ok, I have send you a email