What a nuisance, on my 14.04 the update to kernel 3.13.0-92 from 3.13.0-91 gave me a nasty surprise. VBox is unable to load the modules because they are unsigned. I have the identical problem as described by Fayce66 here https://forums.virtualbox.org/viewtopic.php?f=7&t=77363&start=15#p361135 A workaround (rather complicated) is also nicely laid out. I haven't tried it and hope that a new kernel or VBox update will remedy the problem. (There was also recently a grub2 update, and if I remember correctly, I was presented with an option to disable secure boot). Anyone running VBox on a system with secure boot enabled notice this ? Edit: I will just turn off secure boot whenever running VBox. (For now).