Rudder

Every time I forgot to tell, because it doesn't really bothers me, but now I saw it again and thought you might want to be aware of this. The animated gif at the loading page (I assume it's an animated gif) doesn't work. Only the very first install of Rudder ( I think that was 2.4 or 2.5) it worked and after it stopped. Rudder still loads and works so I don't care really, but maybe others do. I really Don't know if I am the only one and why it doesn't work. My Rudder server is Ubuntu (12.04) and my desktop is Ubuntu (13.10) as well. My browser is Firefox for Ubuntu 17.0.1. Screenshot is attached.