I get a blank desktop screen. I'm not able to use Unity 2D at all. When I type unity-2d-launcher --reset in the terminal, I get the following error. please help.
(unity-2d-launcher:6622): GdkPixbuf-WARNING **: Bug! gdk-pixbuf loader 'png' didn't set an error on failure.
(unity-2d-launcher:6622): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:1230:46: Failed to load image '/usr/share/themes/Ambiance/gtk-3.0/assets/slider.png': reason not known, probably a corrupt image file
(unity-2d-launcher:6622): GdkPixbuf-WARNING **: Bug! gdk-pixbuf loader 'png' didn't set an error on failure.
(unity-2d-launcher:6622): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:1234:55: Failed to load image '/usr/share/themes/Ambiance/gtk-3.0/assets/slider_prelight.png': reason not known, probably a corrupt image file
(unity-2d-launcher:6622): GdkPixbuf-WARNING **: Bug! gdk-pixbuf loader 'png' didn't set an error on failure.
(unity-2d-launcher:6622): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:1238:55: Failed to load image '/usr/share/themes/Ambiance/gtk-3.0/assets/slider_vertical.png': reason not known, probably a corrupt image file
(unity-2d-launcher:6622): GdkPixbuf-WARNING **: Bug! gdk-pixbuf loader 'png' didn't set an error on failure.
(unity-2d-launcher:6622): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:1242:64: Failed to load image '/usr/share/themes/Ambiance/gtk-3.0/assets/slider_prelight_vertical.png': reason not known, probably a corrupt image file
(unity-2d-launcher:6622): GdkPixbuf-WARNING **: Bug! gdk-pixbuf loader 'png' didn't set an error on failure.
(unity-2d-launcher:6622): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:1298:73: Failed to load image '/usr/share/themes/Ambiance/gtk-3.0/assets/scrollbar_handle_vertical.png': reason not known, probably a corrupt image file
(unity-2d-launcher:6622): GdkPixbuf-WARNING **: Bug! gdk-pixbuf loader 'png' didn't set an error on failure.
(unity-2d-launcher:6622): Gtk-WARNING **: Theme parsing error: gtk-widgets.css:1315:64: Failed to load image '/usr/share/themes/Ambiance/gtk-3.0/assets/scrollbar_handle.png': reason not known, probably a corrupt image file
unity-2d-launcher: symbol lookup error: /usr/lib/libdconf-qt.so.0: undefined symbol: _ZNK15QDBusConnection15internalPointerEv