How do I refresh the icon cache?

Solution 1:

run the following in a terminal:

sudo update-icon-caches /usr/share/icons/*

You need to:

Note: hicolor is the default theme which app developers should use. if you're making an icon theme, refresh your icon theme's folder instead.

sudo touch /usr/share/icons/hicolor ~/.local/share/icons/hicolor
sudo gtk-update-icon-cache

See (the only documentation I can find for this): https://fedoraproject.org/wiki/Packaging:Scriptlets#Icon_Cache

At the terminal command prompt type:

$ unity

This will update your *.desktop icons in the Launcher.

If the problem is not the Ubuntu Launcher but the application itself take a look http://stackoverflow.com for programming resolutions.

A similar issue to this is answered at https://stackoverflow.com/questions/5315359/custom-libindicator-icon-is-not-displayed/6503807#6503807

Also look at: https://developer.gnome.org/gtk3/stable/gtk-update-icon-cache.html