I'm experiencing this issue too. My session is plain openbox with some environment tweaks: export XDG_CURRENT_DESKTOP=OPENBOX export GTK2_RC_FILES="$XDG_CONFIG_HOME/gtkrc-2.0:/etc/gtk-2.0/gtkrc" export QT_STYLE_OVERRIDE=gtk qt5 apps get theme successfully, but fail to get icons, all icons are missing.