error during dist-upgrade from 11.04 to 11.10

[Massimiliano Arione]

This is the text of error received:

After your package information was updated the essential package 'ubuntu-minimal' can not be found anymore.
This indicates a serious error, please report this bug using the command 'ubuntu-bug update-manager' in a terminal and include the files in /var/log/dist-upgrade/ in the bug report.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: update-manager 1:0.150.3
ProcVersionSignature: Ubuntu 2.6.38-12.51-generic-pae 2.6.38.8
Uname: Linux 2.6.38-12-generic-pae i686
Architecture: i386
Date: Thu Oct 13 18:14:58 2011
GConfNonDefault:
 /apps/update-manager/check_new_release_ignore=
 /apps/update-manager/first_run=false
 /apps/update-manager/show_details=true
 /apps/update-manager/window_size=(751,802)
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release i386 (20091028.5)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=it_IT:en
 PATH=(custom, user)
 LANG=it_IT.UTF-8
 SHELL=/bin/bash
SourcePackage: update-manager
UpgradeStatus: Upgraded to natty on 2011-10-13 (0 days ago)

[Walter Garcia-Fontes (walter-garcia)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 873468 , so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.