VirtualBox VERR_VM_DRIVER_VERSION_MISMATCH on Ubuntu

Check what version of virtualbox you installed

dpkg --list 'virtualbox*'

may be it's not aligned with the Extension pack.

Remove your installation

sudo apt-get autoremove 'virtualbox*'

Don't install fron Ubuntu repositories but run a fresh installation following the instuctions from official Oracle Virtualbox Download page about Debian-based Linux distributions.

Check that Virtualbox is running before installing the Extension pack.

I've removed all the virualbox packages:

sudo apt-get purge 'virtualbox*'

Then I've installed virtualbox v.5

sudo apt-get install virtualbox-5.0

After that I've enabled virtualization in BIOS. Now it works.

I had the same error starting a vm client in ubuntu 16.4 .

Coincidentally I noticed in the file /var/crash/_usr_lib_virtualbox_VirtualBox.0.crash the following message:

Title: VirtualBox crashed with SIGABRT in QMessageLogger::fatal() UnreportableReason: Sie haben einige veraltete Paketversionen installiert. Bitte aktualisieren Sie die folgenen Pakete und prüfen Sie, ob das Problem danach noch auftritt:

virtualbox-dkms

Translated: You have some outdated package versions installed. Please update the following packages and check, if the problem still occurs after that:

After the command:

sudo apt-get install --only-upgrade virtualbox-dkms

all was OK :)