I seriously doubt that you have virtualbox-guest-x11 package installed. [ 29.401] (WW) Warning, couldn't open module vboxvideo [ 29.401] (II) UnloadModule: "vboxvideo" [ 29.401] (II) Unloading vboxvideo [ 29.401] (EE) Failed to load module "vboxvideo" (module does not exist, 0) Could you double check, please?