Well, Google pointed me to someone more clever than me: http://askubuntu.com/questions/762084/problem-upgrade-15-10-to-16-04 ( Now why didn't the do-release-upgrade process tell me there was a /var/log/dist-upgrade/main.log ?) So, my problem seems to be: $ grep ERROR /var/log/dist-upgrade/main.log 2016-08-01 11:34:27,800 ERROR Dist-upgrade failed: 'The package 'kubuntu-desktop-trinity' is marked for removal but it is in the removal blacklist.' hmmm... Well, I don't have too much time and grief invested in this install so far... So, I'll drop to the command line, apt-get remove kubuntu-desktop-trinity. Then try the sudo do-release-upgrade again. If that flys, I'll reinstall kubuntu-desktop-trinity. If ALL THAT works, I'll report back. Jonesy On Mon, 1 Aug 2016, Jonesy wrote: >I've just installed the Trinity LiveCD > > tde-ubuntu-14.04-desktop-r14.0.3-amd64.iso > >and performed all the updates. >I commented out the entries in >/etc/apt/sources.list.d/libreoffice-trinity.list > -and- >/etc/apt/sources.list.d/trinity.list > >and did a sudo do-release-upgrade >to upgrade to xenial (16.04) >and received the following: > > >|Checking package manager >|Reading package lists... Done >|Building dependency tree >|Reading state information... Done >|Building data structures... Done >| >|Calculating the changes| >| >|Calculating the changes >| >|Could not calculate the upgrade >| >|An unresolvable problem occurred while calculating the upgrade. >| >|This can be caused by: >|* Upgrading to a pre-release version of Ubuntu >|* Running the current pre-release version of Ubuntu >|* Unofficial software packages not provided by Ubuntu >| >|If none of this applies, then please report this bug using the >|command 'ubuntu-bug ubuntu-release-upgrader-core' in a terminal. >| >|Restoring original system state >| >|Aborting > >I don't see how any of the "This can be caused by" pertain. > >I have done this process successfully with the _32bit_ Trinity LiveCD > >Where to start? >Jonesy > -- *** Note: I've long ago moved to the @jonz.net domain for email, vs. the @config.com -- used from 1999 to July, 2014 Marvin L Jones | Marvin | W3DHJ | linux Pueblo, Colorado | @ | Jonesy | FreeBSD __ 38.238N 104.547W | jonz.net | DM78rf | OS/2 SK