if it's about the blood elf Cavalry icon, it's because it does not exist.
It isn't in the import manager : /
otherwise, are you sure you imported them to:
ReplaceableTextures\CommandButtons\
and
ReplaceableTextures\CommandButtonsDisabled\
?
And if you don't have a disabled icon, it should not affect the hero/unit aslong as it is "Availible" but when it's immobilized, dead, or unavailible somehow, the disabled icon kicks in and then there comes a green box.
So, the disabled one is not necessary, but I guess it looks alot better with it.
Actually, Alot of icons that are in use are gone when I check the import manager...
Dunno if this is some sort of error on my side? but I don't think so...
Also, on hero abilities when researching, I found the green icon issue!
Error Found!
You must enter an icon to use in the Research box aswell, otherwise when learning an ability, the icon appears green!
And I found some leaks in the map, but I guess that doesn't matter since it's this small a size? And when it's supposed for 1 player
Hope this has been to any help!
/Mumbis