update-manager crashed with AttributeError in _try_show_release_notes_textview(): 'Window' object has no attribute 'window'

[Rly]

its not updating the ubuntu current version to the latest version. Every time I press upgrade in update manager, the update manager freezes and remains frozen.

ProblemType: Crash
DistroRelease: Ubuntu 11.10
Package: update-manager 1:0.152.18
ProcVersionSignature: Ubuntu 3.0.0-11.18-generic 3.0.4
Uname: Linux 3.0.0-11-generic i686
ApportVersion: 1.23-0ubuntu1
Architecture: i386
Date: Thu Oct 10 07:24:36 2013
ExecutablePath: /usr/bin/update-manager
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Beta i386 (20110921.2)
InterpreterPath: /usr/bin/python2.7
PackageArchitecture: all
ProcCmdline: /usr/bin/python /usr/bin/update-manager
ProcEnviron:
 SHELL=/bin/bash
 PATH=(custom, no user)
 LANG=en_US.UTF-8
PythonArgs: ['/usr/bin/update-manager']
SourcePackage: update-manager
Title: update-manager crashed with AttributeError in _try_show_release_notes_textview(): 'Window' object has no attribute 'window'
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make this software better. This particular crash has already been reported and is a duplicate of bug #859862, so 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. Please continue to report any other bugs you may find.