Unable to upgrade from 14.04 to 14.10 "Cannot Calculate Upgrades"

I just finished backing up my system and when I try to upgrade to Utopic Unicorn, I get the error "Cannot Calculate the upgrades." I ran the upgrade by sudo apt-get dist-upgrade, sudo do-release-upgrade after the GUI method failed, they all gave the same error.

The feedback gives some recommendations:

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 

I am not upgrading to a pre-release version nor coming from one, I'm going from Ubuntu 14.04 LTS to 14.10. I have no broken packages and I have unchecked all my non-official software sources in the 'Software & Updates' manager.

My guess left is the Unofficial software packages not provided by Ubuntu. If anyone could give any help as to how to check for unofficial packages using Synaptic or another, my appreciation.

Are there any other factors that may be causing this error and how would I go about checking/fixing those?

Thanks.

Edit: I have no broken or held packages. Everything is up-to-date, and restarting everything or anything has no effect.

So I managed to solve the issue, but I am unaware as to how I did so. If you have any idea, I'd still like to know what it is I did that caused the resolution.

Here's exactly what I did.

I ran dist-upgrade and apt-get update/upgrade like a madman, continuously checking my broken and held packages in synaptic, of which I never had any. I had a few leftover packages like ROS libraries which I removed because I didn't want them anyways.

After a two days of waiting, I decided to look at the question referenced to by https://askubuntu.com/users/342922/user342922 . I peered into /var/log/dist-upgrade/apt.log and after seeing some reference to the ROS Libs I removed, I deleted that log file.

Only after I deleted that log file did dist-upgrade ever work. Any Ideas as to why this may have occurred? If prompted I'll move this to a new question, but it's not a pressing matter, just interested.

My odd solution: delete the apt.log file for dist-upgrade.