I work with Debian Stretch and after my update today I was not able to restart my VM VirtualBox.
the new version of VirtualBox: 5.1_5.1.6-110634:
virtualbox-5.1_5.1.6-110634 ~ ~ Debian stretch_amd64.deb
The expansion pack will not install, and this seems to be an error in the official deb VirtualBox.
I tried with Debian deb deposit and with the deb of VirtualBox, in both cases the same problem.
I found where the error comes:
the command used by the VirtualBox installer contains an error: ' is forget in the command
correction :
VirtualBox is started,
File / Parameters / extensions have installed a new extension,
we chose the right pack and valid,
a window opens for the root password (even with the correct password no installation, no error message)
the command used is displayed and it contains errors:
we must create the / tmp / VBoxExtPackHelper-3trj56 / stderr and stdout files in that directory, empty files
# Mkdir / tmp / VBoxExtPackHelper-3trj56 /
#touch / tmp / VBoxExtPackHelper-3trj56 / stderr
#touch / tmp / VBoxExtPackHelper-3trj56 / stdout
copy the command in a terminal as root and correct the error:
put single quotes around Oracle VM VirtualBox Extension Pack to get: --name 'Oracle VM VirtualBox Extension Pack'
and then everything settles