problems upgrading from 14.04 to 16.04

[J.L. Blom]

On 26/09/16 12:33, Colin Law wrote:
> On 26 September 2016 at 11:26, J.L. Blom <joep at neuroweave.nl> wrote:
>> ________________________________________
>> joep at laguna:~$ sudo apt update
>> [sudo] password for joep:
>> Err:1 http://nl.archive.ubuntu.com/ubuntu xenial InRelease
>>    Could not resolve 'nl.archive.ubuntu.com'
> Work on solving this first. It may well just be a temporary problem
> with the server. Try again and see if it is ok. To check the server is
> accessible you can go to http://nl.archive.ubuntu.com/ubuntu in your
> browser. It is ok for me at the moment.
>
> Colin
>
>
>
Colin, Thanks for the quick reply. Yes, it now is reachable again. 
However, the problem is not solved. See the output:

_______________________________

joep at laguna:~$ sudo apt-get -f install
Reading package lists... Done
Building dependency tree
Reading state information... Done
Correcting dependencies... failed.
The following packages have unmet dependencies:
  libstdc++6 : Depends: gcc-5-base (= 5.4.0-6ubuntu1~16.04.2) but 
5.4.1-2ubuntu1~14.04 is installed
               Breaks: libkolabxml1 (<= 1.1.0-3) but 1.0.1-0ubuntu3 is 
installed
               Breaks: libstdc++6:i386 (!= 5.4.0-6ubuntu1~16.04.2) but 
6.2.0-3ubuntu11~14.04 is installed
  libstdc++6:i386 : Breaks: libstdc++6 (!= 6.2.0-3ubuntu11~14.04) but 
5.4.0-6ubuntu1~16.04.2 is installed
E: Error, pkgProblemResolver::Resolve generated breaks, this may be 
caused by held packages.
E: Unable to correct dependencies
___________________________________________

It looks like it didn't remove the old libraries but how to solve that 
without breaking much more is my problem.
When I mentioned in my former mail that I solved the problem with the 
graphics not starting and apt-get not working, that was solved by 
installing another version of libstdc++6:amd64 by downloading 
libstdc++6_5.4.0-6ubuntu1~16.04.2_amd64.deb and installing using dpkg. 
But I don't know how to solve - apparently the same problem - for :i386.
Joep