Trying to enter the settings of any VM causes an incredible, horrible crash that rivals Windows . It doesn't matter which version of Virtualbox you use.
The problem is not Mint nor Virtualbox, but the NVidia driver that remains unused even after the installation using the tool “Additional driver” in the control center.
Solution: Backup the original
sudo mv /usr/lib/xorg/modules/extensions/libglx.so /usr/lib/xorg/modules/extensions/libglx.so.orig
then you create a link to the proper driver version this way:
if the directory /usr/lib/nvidia-current/ exists, use this
sudo ln -s /usr/lib/nvidia-current/xorg/libglx.so /usr/lib/xorg/modules/extensions/libglx.so
otherwise link directly to the specific version this way:
sudo ln -s /usr/lib/nvidia-331t/xorg/libglx.so /usr/lib/xorg/modules/extensions/libglx.so
Now, even without restarting the session, the problem with Virtualbox crash should be solved.