Comment 6 for bug 1272801

> #1 0x00007fa61cfe7ee3 in g_signal_handler_disconnect (instance=0x21, handler_id=140351430766768) at /build/buildd/glib2.0-2.39.3/./gobject/gsignal.c:2572

That instance pointer is suspicious... possibly a NULL structure pointer got dereferenced? Although it's an odd number...