(atril:8776): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:186:14: not a number

(atril:8776): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:186:14: Expected a string.

(atril:8776): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:2749:24: not a number

(atril:8776): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:2749:24: Expected a string.

(atril:8776): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:2940:14: not a number

(atril:8776): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:2940:14: Expected a string.

(atril:8776): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:2946:17: Expected a string.

(atril:8776): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:4083:14: not a number

(atril:8776): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:4083:14: Expected a string.

(atril:8776): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:4088:17: Expected a string.

(atril:8776): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:4729:14: not a number

(atril:8776): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:4729:14: Expected a string.

(atril:8776): Gtk-WARNING **: Theme parsing error: xfce.css:47:16: not a number

(atril:8776): Gtk-WARNING **: Theme parsing error: xfce.css:47:16: Expected a string.

(atril:8776): Gtk-WARNING **: Theme parsing error: lightdm-gtk-greeter.css:16:14: not a number

(atril:8776): Gtk-WARNING **: Theme parsing error: lightdm-gtk-greeter.css:16:14: Expected a string.

(atril:8776): Gtk-WARNING **: Theme parsing error: lightdm-gtk-greeter.css:26:14: not a number

(atril:8776): Gtk-WARNING **: Theme parsing error: lightdm-gtk-greeter.css:26:14: Expected a string.

(atril:8776): Gtk-WARNING **: Theme parsing error: lightdm-gtk-greeter.css:40:16: not a number

(atril:8776): Gtk-WARNING **: Theme parsing error: lightdm-gtk-greeter.css:40:16: Expected a string.

(atril:8776): Gtk-WARNING **: Theme parsing error: lightdm-gtk-greeter.css:96:14: Expected a string.

(atril:8776): Gtk-WARNING **: Theme parsing error: lightdm-gtk-greeter.css:100:16: not a number

(atril:8776): Gtk-WARNING **: Theme parsing error: lightdm-gtk-greeter.css:100:16: Expected a string.

(atril:8776): Gtk-WARNING **: Theme parsing error: lightdm-gtk-greeter.css:279:14: not a number

(atril:8776): Gtk-WARNING **: Theme parsing error: lightdm-gtk-greeter.css:279:14: Expected a string.

(atril:8776): Gtk-WARNING **: Allocating size to EvSidebar 0x5571cda4af80 without calling gtk_widget_get_preferred_width/height(). How does the code know the size to allocate?