Same for me. Also affects (at least) kate and konsole. In kate all icons in the toolbars are missing. dolphin4 and konqueror are not affected. I noticed this after upgrade from xubuntu 15.04 to 15.10. I have reproduced it in a fresh install of xubuntu 15.10 in a VirtualBox.
The icons are missing only in a xubuntu session with xfce4, but in a plasma session everything is fine. So this does not seem to be caused by a missing package.
Same for me. Also affects (at least) kate and konsole. In kate all icons in the toolbars are missing. dolphin4 and konqueror are not affected. I noticed this after upgrade from xubuntu 15.04 to 15.10. I have reproduced it in a fresh install of xubuntu 15.10 in a VirtualBox.
The icons are missing only in a xubuntu session with xfce4, but in a plasma session everything is fine. So this does not seem to be caused by a missing package.