[Linux] 'Inherits=' not working?

[Leinatan]

Since many icons are missing (and that's ok), I wonder why there is no fallback theme by default, and if I try to set a fallback theme, it doesn't work...

I tried to edit /usr/share/icons/Luv/index.theme

Line 39: Inherits=
to
Line 39: Inherits=hicolor

But nothing happened, although this icon theme is robust and complete.
(also tried 'breeze' and 'breath', no success)
I tried logging out, even rebooting. The added parameter changes nothing....

Do you know if an extra step is required?
Thank you, awesome icons btw

[UriHerrera]

You may rebuild the icon.cache file after you make your changes to the index.theme file so that your changes are picked up when loading the icon theme.

[Leinatan]

Oh, and how can I do this?

[UriHerrera]

Oh, and how can I do this?

You can try with:

update-icon-caches /path/to/icons

Or

gtk-update-icon-cache -q -t -f /path/to/icons