這個警告訊息，通常是Gtk overlay-scrollbar有被動過導致的

訊息類似於:
(gedit:8544): Gtk-WARNING **: GtkScrolledWindow 0x1e526c0 is mapped but visible child GtkScrollbar 0x1e5a760 is not mapped

直接重新安裝就能排除不斷出現的大量錯誤

sudo apt-get --reinstall install overlay-scrollbar