Hello,

I'm using ubuntu 12.04 LTS on a laptop.

It used to work well, but now when I try to open the software center, it opens and then closes almost immediately. If I launch it from the terminal, I get the following messages (see at the end of my post)

I don't manage to interpret the error messages. Maybe someone here knows better what they mean. What should I do?

Thank you

2012-12-22 09:37:52,173 - softwarecenter.ui.gtk3.app - INFO - setting up proxy 'None'
2012-12-22 09:37:52,178 - softwarecenter.db.database - INFO - open() database: path=None use_axi=True use_agent=True
2012-12-22 09:37:52,548 - softwarecenter.backend.reviews - WARNING - Could not get usefulness from server, no username in config file
2012-12-22 09:37:52,690 - softwarecenter.ui.gtk3.app - INFO - show_available_packages: search_text is '', app is None.
2012-12-22 09:37:53,147 - 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 145, in open
self._cache = apt_pkg.Cache(progress)
SystemError: E:Encountered a section with no Package: header, Eroblem with MergeList /var/lib/apt/lists/www.mendeley.com_repositories_ubuntu_stable_en, E:The package lists or status file could not be parsed or opened.
2012-12-22 09:37:55,695 - 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.AVAILA BLE)
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__'