[SOLVED]Error Installing Extension Pack 6.1.12 (Headless Debian 9)

[Scorpadox]

I'm a part-time hobbies using Linux and don't have too much experience.
I recently upgraded from Debian 8 to Debian 9 (Headless).
And after some fuss, I was able to uninstall VBox 5.1 and install 6.1.12
I'm using MobaXTerm to SSH.
VBox runs and using "File > Check For Updates", confirmed I'm running the most recent version.
All instructions for Installing Extension Pack say to double click it... but this is headless, so command line for me...

In VBox, I went to Tools > Welcome > Preferences > Extentions > Add > "Oracle_VM_VirtualBox_Extension_Pack-6.1.12.vbox-extpack" > Open > Install > Agree
Then I get this error:

Failed to install the Extension Pack /home/user/Oracle_VM_VirtualBox_Extension_Pack-6.1.12.vbox-extpack.

The installer failed with exit code 127: Error creating textual authentication agent: Error opening current controlling terminal for the process (`/dev/tty'): No such device or address.

Result Code: NS_ERROR_FAILURE (0x80004005)
Component: ExtPackManagerWrap
Interface: IExtPackManager {70401eef-c8e9-466b-9660-45cb3e9979e4}

I'm at a loss. Googeling returns results from V4/V5 where the solution was to use the same version of Ext Pack and VBox... But unless I'm wrong, I'm 6.1.12 for both.

[Scorpadox]

Solved:

1. I had to add my user account to the SUDO user group by logging in as root

   Code: Select all

   su - root

   then running

   Code: Select all

   usermod -aG sudo myUserName

2. I then used VBoxManage to install the extpack

   Code: Select all

   sudo VBoxManage extpack install ./Oracle_VM_VirtualBox_Extension_Pack-6.1.12.vbox-extpack

[scottgus1]

Thanks for letting us know how you solved this, Scorpadox! It was beyond me to suggest any ideas.