Sorry, it seems too flaky, makes me nervous to use as it is.
I reinstalled gdk-pixbuf2 (2.36.8-2) and it worked, but only once. After that, back to the same problem. I also tried rebooting.
I saw you're using a non-standard file picker. Perhaps a future version can use a different file picker?
I also saw this message
Gtk-Message: Failed to load module "canberra-gtk-module"
(DashMasternodeTool-0.9.6:5218): Gtk-WARNING **: Theme parsing error: gtk.css:17:21: '-gtk-outline-radius' is not a valid property name
That's a sound module? It's already installed (and reinstalled).
I don't know what to say, all my other apps are working just fine.