When I put file icon.png in to the usr/share/icons folder (doing that as root), I can't set that icon on my application latter on. When I try, I navigate to the icons folder, but that icon doesn't work. I can't even see it by navigating to icons folder one more time. I can see it or only open it when I go to the icons folder with root privileges.

This happens on Linux Mint 17, 32 bit.

As you can see, while in regular mode, I can't see the picture, and while in root mode, I can edit it, so how could I be able to set it as my application icon?