unable to upgrade ubuntu from 14.04 to 16.04

[Colin Law]

On 26 March 2016 at 09:23, Colin Law <clanlaw at gmail.com> wrote:
> On 26 March 2016 at 09:10, 李白|字一日 <calidion at gmail.com> wrote:
>> failed still.
>
> Please don't top post, the convention on this list to to insert the
> reply at appropriate point(s) in previous message.  Thanks.
>
> Can you copy/paste the full output from
> sudo  do-release-upgrade  -d

Also have you got anything installed from non-standard repositories
(ppas or others)?  Have a look in Software & Updates > Other Software
to see if you have any other repositories enabled.

If yes purge any ppas you are using (use ppa-purge) and uninstall any
packages from non-standard repositories and disable those repos.  You
can find what the packages are in Synaptic.

Then in Synaptic uninstall anything in the section 'Installed (local
or obsolete)' except ubuntu-extras-keyring.

Then do the update, dist-upgrade and do-release upgrade again.

By the way, I presume that you made sure you had everything important
backed up before starting any of this.

Colin