problems with virtualbox

[Ralf Mardorf]

On Sat, 11 Aug 2018 10:55:53 +1000, Peter wrote:
>I added my user to vboxusers. This solves most of the problems [snip] I
>will start testing later today.

Don't count your chickens before they're hatched. Unlikely the issue is
solved.

On Fri, 10 Aug 2018 19:36:18 +1000, Peter wrote:
>I installed 64 bit Ubuntu 16.04 on one machine. This was a clean
>install wiping the disk clean. I then installed the latest Oracle
>Virtual Box (5.2.16) with th extension pack an user extension. I then
>ported back my original virtual box [snip]
>
>On looking at the new 64 bit installation the problem is clearly with 
>the USB interface. If is sect USB 2.0 the machine will not start and 
>complains about a possible incompatible version of the extension pack.

IIUC you are using the binary from Oracle, not the package from Ubuntu.
How did you "install" the extension pack?

You perhaps downloaded and saved the extension pack, which is not the
same as making it available for usage with your virtualbox machines. By
porting back the settings of your original virtual box, the used
path/file of the extension pack is broken. Btw. how did you port back
your original virtual box?

Go to

File > Preferences... > Extensions

You might use a different path, on my machine the path and the file are

/usr/share/virtualbox/extensions/Oracle_VM_VirtualBox_Extension_Pack-5.2.16.vbox-extpack