With the Upgrading Ubuntu 12.04 64bit on 14.04 there comes mistake: It could not be determined which system actualizations are available

[barrakuda]

Es konnte nicht ermittelt werden, welche Systemaktualisierungen verfügbar sind

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

Falls nichts von dem zutrifft, melden Sie diesen Fehler bitte, indem Sie den Befehl »ubuntu-bug ubuntu-release-upgrader-core« in einem Terminal ausführen.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: update-manager 1:0.156.14.17
ProcVersionSignature: Ubuntu 3.2.0-68.102-generic 3.2.62
Uname: Linux 3.2.0-68-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu17.7
Architecture: amd64
Date: Tue Aug 26 07:52:00 2014
GsettingsChanges:
 com.ubuntu.update-manager first-run false
 com.ubuntu.update-manager launch-time 1409031732
 com.ubuntu.update-manager show-details true
 com.ubuntu.update-manager window-height 740
 com.ubuntu.update-manager window-width 942
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
MarkForUpload: True
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: update-manager
Symptom: ubuntu-release-upgrader-core
UpgradeStatus: Upgraded to precise on 2014-08-26 (0 days ago)
VarLogDistupgradeTermlog:

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.