Upgrading to 16.04

[Ralf Mardorf]

On Fri, 19 Aug 2016 11:48:57 +1000, Peter wrote:
>I then downloaded and installed
>virtualbox-5.1_5.1.4-110228~Ubuntu~xenial_amd64deb.  The installation
>failed. I have tried several download from various sites, with the
>same result.

You need to describe what failed, IOW post the commands you run
and the output you get. You even don't clearly mention if you tried to
install a manually downloaded package or if you added the virtualbox
repository. What are those obscure sites, that were your sources for
downloading the package? I suspect you downloaded the package manually,
instead of using the available repository. Consider to follow the
advices from the original virtualbox download site. However, if you
downloaded the package manually and not from a repository, you can't
simply install it with dpkg -i, without installing the dependencies,
too. But maybe you already used the correct commands and perhaps dkms
failed or what ever else. Do you hope that some of the subscribers use
crystal balls ;)?

Regards,
Ralf

PS:

sudo apt update && sudo gdebi virtualbox-5.1_5.1.4-110228~Ubuntu~xenial_amd64deb

or

sudo apt update && sudo dpkg -i --force-depends virtualbox-5.1_5.1.4-110228~Ubuntu~xenial_amd64deb && sudo apt-get -f install