I can't see custom icons! help me!

[SOA_Agito]

Whenever I am playing FoC or many other good games with custom icons, I instead see shields, fists, scratchy icons, or other things of the like. Originally I figured that it did not really make much of a difference, but seeing a screenshot of working icons changed my mind. I think it is because I am missing a program (codec maybe?) that can view them. If anyone could suggest a program with a link or such, I would be extremely grateful.

Another note, I can see the custom icons for Anime Wars and Fate/Another.