Sorry, I thought the automatically-filled details would give context, so
I wasn't very clear in the description.
I know how to start the upgrade from 12.04 to 14.04, but when I do that
I get the error message I pasted at the top of the description. I've
amended the description to reflect this.
I
Public bug reported:
Message says:
Could not determine 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 pro
Public bug reported:
Happens every time, and upgrade cannot proceed.
ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: update-manager 1:0.156.14.13
ProcVersionSignature: Ubuntu 3.2.0-65.99-generic-pae 3.2.60
Uname: Linux 3.2.0-65-generic-pae i686
NonfreeKernelModules: nvidia
ApportVersion: 2.
