Cannot upgrade Kubuntu 11.10 to 12.04

[Alessander Botti Benevides]

I don't want to upgrade to proposed or devel releases. I want the stable 12.04 LTS, but "do-release-upgrade -c" shows no releases. Concerning the files collected by ubuntu-bug, I think most of them are not relevant, as they are related to an upgrade done in 2011.

$ do-release-upgrade -c
Checking for a new Ubuntu release
No new release found

$ do-release-upgrade -c -p
Checking for a new Ubuntu release
New release '12.04 LTS' available.
Run 'do-release-upgrade' to upgrade to it.

$ do-release-upgrade -c -d
Checking for a new Ubuntu release
New release '12.04.1 LTS' available.
Run 'do-release-upgrade' to upgrade to it.

$ lsb_release -rd
Description: Ubuntu 11.10
Release: 11.10

$ do-release-upgrade -V
do-release-upgrade: version 0.152.25.4

$ apt-cache policy update-manager-core
update-manager-core:
  Installed: 1:0.152.25.13
  Candidate: 1:0.152.25.13
  Version table:
 *** 1:0.152.25.13 0
        500 http://archive.ubuntu.com/ubuntu/ oneiric-updates/main amd64 Packages
        100 /var/lib/dpkg/status
     1:0.152.25.12 0
        500 http://security.ubuntu.com/ubuntu/ oneiric-security/main amd64 Packages
     1:0.152.25 0
        500 http://archive.ubuntu.com/ubuntu/ oneiric/main amd64 Packages

P.s.: The original outputs were in Portuguese, so I translated them to English.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: update-manager-core 1:0.152.25.13
ProcVersionSignature: Ubuntu 3.0.0-30.47-generic 3.0.57
Uname: Linux 3.0.0-30-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 1.23-0ubuntu4.1
Architecture: amd64
Date: Thu Jan 17 17:30:38 2013
InstallationMedia: Kubuntu 10.10 "Maverick Meerkat" - Release amd64 (20101008)
ProcEnviron:
 LANGUAGE=pt_BR:pt:en
 PATH=(custom, no user)
 LANG=pt_BR.UTF-8
 SHELL=/bin/bash
SourcePackage: update-manager
UpgradeStatus: Upgraded to oneiric on 2011-12-29 (384 days ago)
mtime.conffile..etc.update.manager.release.upgrades: 2013-01-17T16:58:10.506821

[Alessander Botti Benevides (alessanderbotti)]

Both /var/lib/update-manager/meta-release and /var/lib/update-manager/meta-release-lts were corrupted. I renamed these files to backup them and then ran muon (the package manager of Kubuntu 11.10), what created new files and fixed the problem.