i get an error message from the ubuntu software center every time i try to download anything. i just started using linux and am trying to figure out how to remedy this.From what i understand so far i need to use the terminal somehow. i tried opening software center from the terminal and recieved this error message below.Any help would be greatly appreciated, otherwise ill spend hours sorting through forums untill i understand it myself lol.


2012-10-20 15:09:57,629 - softwarecenter.ui.gtk3.app - INFO - setting up proxy 'None'
2012-10-20 15:09:57,635 - softwarecenter.db.database - INFO - open() database: path=None use_axi=True use_agent=True

2012-10-20 15:10:00,482 - softwarecenter.backend.reviews - WARNING - Could not get usefulness from server, no username in config file
2012-10-20 15:10:00,886 - softwarecenter.ui.gtk3.app - INFO - show_available_packages: search_text is '', app is None.
2012-10-20 15:10:00,888 - softwarecenter.db.pkginfo_impl.aptcache - INFO - aptcache.open()
Traceback (most recent call last):
File "/usr/share/software-center/softwarecenter/db/pkginfo_impl/aptcache.py", line 243, in open
self._cache = apt.Cache(GtkMainIterationProgress())
File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 102, in __init__
self.open(progress)
File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 146, in open
self._depcache = apt_pkg.DepCache(self._cache)
SystemError: E:The package google-chrome-stable needs to be reinstalled, but I can't find an archive for it.
2012-10-20 15:10:04,225 - softwarecenter.db.enquire - ERROR - _get_estimate_nr_apps_and_nr_pkgs failed
Traceback (most recent call last):
File "/usr/share/software-center/softwarecenter/db/enquire.py", line 115, in _get_estimate_nr_apps_and_nr_pkgs
tmp_matches = enquire.get_mset(0, len(self.db), None, xfilter)
File "/usr/share/software-center/softwarecenter/db/appfilter.py", line 89, in __call__
if (not pkgname in self.cache and
File "/usr/share/software-center/softwarecenter/db/pkginfo_impl/aptcache.py", line 263, in __contains__
return self._cache.__contains__(k)
AttributeError: 'NoneType' object has no attribute '__contains__'
Traceback (most recent call last):
File "/usr/bin/software-center", line 176, in <module>
app.run(args)
File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1422, in run
self.show_available_packages(args)
File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1352, in show_available_packages
self.view_manager.set_active_view(ViewPages.AVAILABLE)
File "/usr/share/software-center/softwarecenter/ui/gtk3/session/viewmanager.py", line 154, in set_active_view
view_widget.init_view()
File "/usr/share/software-center/softwarecenter/ui/gtk3/panes/availablepane.py", line 171, in init_view
self.apps_filter)
File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 238, in __init__
self.build(desktopdir)
File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 511, in build
self._build_homepage_view()
File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 271, in _build_homepage_view
self._append_whats_new()
File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 450, in _append_whats_new
whats_new_cat = self._update_whats_new_content()
File "/usr/share/software-center/softwarecenter/ui/gtk3/views/catview_gtk.py", line 439, in _update_whats_new_content
docs = whats_new_cat.get_documents(self.db)
File "/usr/share/software-center/softwarecenter/db/categories.py", line 124, in get_documents
nonblocking_load=False)
File "/usr/share/software-center/softwarecenter/db/enquire.py", line 317, in set_query
self._blocking_perform_search()
File "/usr/share/software-center/softwarecenter/db/enquire.py", line 212, in _blocking_perform_search
matches = enquire.get_mset(0, self.limit, None, xfilter)
File "/usr/share/software-center/softwarecenter/db/appfilter.py", line 89, in __call__
if (not pkgname in self.cache and
File "/usr/share/software-center/softwarecenter/db/pkginfo_impl/aptcache.py", line 263, in __contains__
return self._cache.__contains__(k)
AttributeError: 'NoneType' object has no attribute '__contains__'

Try this command from a terminal:

For further help, please look at this thread:

Ubuntu Software Center in 12.04 does not open

Thanks!