14.04 - 15.04/error updating

[Amon Rivsky]

An error occurred, please run Package Manager from the right-click menu or apt-get in a terminal to see what is wrong. The error message was: ' Error: Marking the upgrade (E:Error, pkgProblemResolver::Resolve generated breaks, this maybe caused by held packages.)' . This usually means that your installed packages have unmet dependencies

1) 14.04
2) 1:0.196.14
3) upgrade from 14.04 to 15.04
4) an error appeared

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: ubuntu-release-upgrader-core 1:0.220.8
ProcVersionSignature: Ubuntu 3.13.0-74.118-generic 3.13.11-ckt30
Uname: Linux 3.13.0-74-generic i686
NonfreeKernelModules: wl
ApportVersion: 2.14.1-0ubuntu3.19
Architecture: i386
CrashDB: ubuntu
CurrentDesktop: Unity
Date: Sat Jan 16 13:09:37 2016
InstallationDate: Installed on 2014-02-07 (707 days ago)
InstallationMedia: Ubuntu 13.10 "Saucy Salamander" - Release i386 (20131016.1)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
Symptom: ubuntu-release-upgrader
UpgradeStatus: Upgraded to trusty on 2016-01-16 (0 days ago)
VarLogDistupgradeTermlog:

mtime.conffile..etc.update.manager.release.upgrades: 2016-01-16T11:19:46.574104