I have a strange bug under Ubuntu Gnome 16.04. After I apply Numix theme in the apperance (with numix circle icon theme but its not depend for the problem), the pdfchain application won't start. If I change back to Adwaita theme, the pdfchain will start normally. With terminal:
(pdfchain:5507): Gtk-WARNING **: Theme parsing error: gtk.css:2903:18: '-gtk-icon-shadow' is not a valid property name
(pdfchain:5507): Gtk-WARNING **: Theme parsing error: gtk.css:2908:18: '-gtk-icon-shadow' is not a valid property name
(pdfchain:5507): Gtk-WARNING **: Theme parsing error: gtk.css:2913:18: '-gtk-icon-shadow' is not a valid property name
(pdfchain:5507): Gtk-WARNING **: Theme parsing error: gtk.css:2918:18: '-gtk-icon-shadow' is not a valid property name
(pdfchain:5507): Gtk-WARNING **: Theme parsing error: gtk.css:2923:18: '-gtk-icon-shadow' is not a valid property name
(pdfchain:5507): Gtk-WARNING **: Theme parsing error: gtk.css:2928:18: '-gtk-icon-shadow' is not a valid property name
(pdfchain:5507): Gtk-WARNING **: Theme parsing error: gtk.css:2933:18: '-gtk-icon-shadow' is not a valid property name
(pdfchain:5507): Gtk-WARNING **: Theme parsing error: gtk.css:2938:18: '-gtk-icon-shadow' is not a valid property name
PDF Chain 0.4.4 - A graphical user interface for the PDF Toolkit
Segmentation fault
So, strange, if I start the app with Adwaita, and switch back to Numix, its working, but if I quit and try to start again, it won't start.
Any idea to fix it?