Solution for: Gtk-WARNING **: Error loading theme icon

How to fix Gtk fatal error of PNG images.

I'm still running RawTherapee 2.4.11 instead of version 3 or 4. This is simply because I find it a lot more easy to use and I still like the the more aggressive noise reduction in it.

After upgrading to Mint 14, I've received errors when trying to start it, errors like: Gtk-WARNING **: Error loading theme icon 'text-x-generic' for stock: Fatal error reading PNG image file: Invalid IHDR data

The solution is quite simple, though not really trivial: update icon cache for fallback icon sets. This will do ( run it as root ):

for i in /usr/share/icons/*; do sudo gtk-update-icon-cache $i; done