Theme should have 'app' folder as top subfolder?

[LinuxOnTheDesktop]

It seems that because paper has no 'apps' subfolder, at least one program - namely, Rainlendar - has problems with the Paper theme. See here. Perhaps indeed all icon themes should have 'apps' as a top-level subfolder.

I post this here because for some reason 'https://github.com/snwh/paper-gtk-theme/issues' has been marked read-only.

EDIT: actually, I think the problem has to do with the index.theme file - or with Mint.