Unable to do updates in Ubuntu 11.10

[Nithin C]

I am using Ubuntu 11.10:

Error shown by update manager:

Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/aptdaemon/worker.py", line 968, in simulate
    trans.unauthenticated = self._simulate_helper(trans)
  File "/usr/lib/python2.7/dist-packages/aptdaemon/worker.py", line 1092, in _simulate_helper
    return depends, self._cache.required_download, \
  File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 235, in required_download
    pm.get_archives(fetcher, self._list, self._records)
SystemError: E:Method has died unexpectedly!, E:Sub-process returned an error code (100), E:Method /usr/lib/apt/methods/ did not start correctly

Error shown by sudo apt-get upgrade command:
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be upgraded:
  app-install-data-partner banshee banshee-extension-soundmenu
  banshee-extension-ubuntuonemusicstore ghostscript ghostscript-cups
  ghostscript-x gnome-settings-daemon kate-data katepart kde-runtime
  kde-runtime-data kdebase-runtime kdelibs-bin kdelibs5-data kdelibs5-plugins
  kdoctools libgs9 libgs9-common libgweather-3-0 libgweather-common
  libkatepartinterfaces4 libkcmutils4 libkde3support4 libkdecore5 libkdesu5
  libkdeui5 libkdewebkit5 libkdnssd4 libkemoticons4 libkfile4 libkhtml5
  libkidletime4 libkio5 libkjsapi4 libkjsembed4 libkmediaplayer4
  libknewstuff3-4 libknotifyconfig4 libkntlm4 libkparts4 libkpty4
  libkrosscore4 libktexteditor4 libmono-zeroconf1.0-cil libnepomuk4
  libnepomukquery4a libnepomukutils4 libplasma3 libpolkit-qt-1-1 libsolid4
  libsoprano4 libthreadweaver4 mobile-broadband-provider-info multisystem
  plasma-scriptengine-javascript soprano-daemon ubuntu-tweak
58 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Failed to exec method /usr/lib/apt/methods/
E: Method has died unexpectedly!
E: Sub-process returned an error code (100)
E: Method /usr/lib/apt/methods/ did not start correctly

Error shown by synaptic package manager when clicking "Mark all Upgrades" and "Apply":
E: Method has died unexpectedly!
E: Sub-process returned an error code (100)
E: Method /usr/lib/apt/methods/ did not start correctly
E: Unable to lock the download directory

[Daniel van Vugt (vanvugt)]

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 659438, 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.