[Q] cm11 theme, icons don't work unless there is a styles (overlays) folder

So as the title says. I'm working on a cm11 theme. I basically want to theme everything except for the "styles" itself because this is an addon theme to another theme. However, if I remove the "overlays" folder, the icons quit working. Anybody know what I'm doing wrong or is this a bug in the themeing app?

Thanks for any help!