I upgrade from Ubuntu 15.10 to 16.04 and since then VirtualBox 5.0.18 isn't starting my VMs anymore. It complains that 'vboxdrv' isn't loaded. So I try to load it and get the following error:
$ sudo modprobe vboxdrv
modprobe: ERROR: could not insert 'vboxdrv': Required key not available
I believe it is related to secure boot which I use and which I want to continue using. Actually with Ubuntu 15.10 secure boot and VirtualBox were working just fine.
Also I tried
$ sudo apt-get --reinstall install virtualbox-dkms which built the kernel module successfully but didn't solve this issue.
Any idea how to get vboxdrv loaded while keeping secure boot enabled?
Update 2: Also I tried executing
sudo mokutil --disable-validation. When executing this command, during the next boot I get prompted to disable secure boot, add a key or hash from disk. Since I don't want to disable secure boot, it seems that this doesn't solve my issue either. Also I want to keep UEFI activated for a parallel Windows installation.
Note: If you don't mind disabling secure boot, see Why do I get "Required key not available" when install 3rd party kernel modules or after a kernel upgrade? instead.