I have the virtualbox installed in my Ubuntu and got this problem.
Failed to access the USB subsystem.
VirtualBox is not currently allowed to access USB devices. You can change this by adding your user to the ‘vboxusers’ group. Please see the user manual for a more detailed explanation.
Solved by using the following
sudo usermod -aG vboxusers
Replace <your username> with the name you use to log in. Type your user password when prompted.
Be sure to log off and back in to finalize the change in permissions