Центр программного обеспечения не открывается и не обновляется Ubuntu [дубликат]

Я не могу открыть Центр программного обеспечения. Когда я все же пытаюсь открыть его, окно открывается на пару минут, а затем закрывается. Когда я попытался запустить в терминале, я получил следующее сообщение:

2015-08-01 21:40:27,619 - softwarecenter.ui.gtk3.app - INFO - setting up proxy 'None'
2015-08-01 21:40:28,289 - softwarecenter.backend.reviews - WARNING - Could not get usefulness from server, no username in config file
2015-08-01 21:40:28,291 - softwarecenter.plugin - INFO - activating plugin '<module 'webapps_activation' from '/usr/share/software-center/softwarecenter/plugins/webapps_activation.pyc'>'
2015-08-01 21:40:28,335 - softwarecenter.db.pkginfo_impl.aptcache - INFO - aptcache.open()
2015-08-01 21:40:29,453 - softwarecenter.backend.reviews - WARNING - error creating bsddb: '(22, 'Invalid argument -- BDB0054 illegal flag combination specified to DB_ENV->open')' (corrupted?)
2015-08-01 21:40:29,454 - softwarecenter.backend.reviews - ERROR - trying to repair DB failed
Traceback (most recent call last):
  File "/usr/share/software-center/softwarecenter/backend/reviews/__init__.py", line 358, in _save_review_stats_cache_blocking
    self._dump_bsddbm_for_unity(outfile, outdir)
  File "/usr/share/software-center/softwarecenter/backend/reviews/__init__.py", line 377, in _dump_bsddbm_for_unity
    0600)
DBInvalidArgError: (22, 'Invalid argument -- BDB0054 illegal flag combination specified to DB_ENV->open')
/usr/lib/python2.7/dist-packages/gi/overrides/GLib.py:535: Warning: Source ID 74 was not found when attempting to remove it
  return super(MainContext, self).iteration(may_block)
Traceback (most recent call last):
  File "/usr/share/software-center/softwarecenter/db/pkginfo_impl/aptcache.py", line 261, in open
    self._cache = apt.Cache(progress)
  File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 107, in __init__
    self.open(progress)
  File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 151, in open
    self._cache = apt_pkg.Cache(progress)
SystemError: E:Encountered a section with no Package: header, E:Problem with MergeList /var/lib/apt/lists/repo.steampowered.com_steam_dists_precise_steam_i18n_Translation-en, E:The package lists or status file could not be parsed or opened.
2015-08-01 21:40:32,046 - 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 281, 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 183, in <module>
    app.run(args)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1378, in run
    self.show_available_packages(args)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1316, in show_available_packages
    self.view_manager.set_active_view(ViewPages.AVAILABLE)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/session/viewmanager.py", line 150, in set_active_view
    view_widget.init_view()
  File "/usr/share/software-center/softwarecenter/ui/gtk3/panes/availablepane.py", line 227, in init_view
    self.cache, self.db, self.icons, self.apps_filter)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/views/lobbyview.py", line 80, in __init__
    self.build()
  File "/usr/share/software-center/softwarecenter/ui/gtk3/views/lobbyview.py", line 326, in build
    self._build_homepage_view()
  File "/usr/share/software-center/softwarecenter/ui/gtk3/views/lobbyview.py", line 121, in _build_homepage_view
    self._append_whats_new()
  File "/usr/share/software-center/softwarecenter/ui/gtk3/views/lobbyview.py", line 255, in _append_whats_new
    whats_new_cat = self._update_whats_new_content()
  File "/usr/share/software-center/softwarecenter/ui/gtk3/views/lobbyview.py", line 240, in _update_whats_new_content
    docs = whats_new_cat.get_documents(self.db)
  File "/usr/share/software-center/softwarecenter/db/categories.py", line 131, in get_documents
    nonblocking_load=False)
  File "/usr/share/software-center/softwarecenter/db/enquire.py", line 330, in set_query
    self._blocking_perform_search()
  File "/usr/share/software-center/softwarecenter/db/enquire.py", line 225, 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 281, in __contains__
    return self._cache.__contains__(k)
AttributeError: 'NoneType' object has no attribute '__contains__'
montem@Zalman:~$ Traceback (most recent call last):
  File "/usr/share/software-center/update-software-center-agent", line 81, in <module>
    cache = apt.Cache(memonly=True)
  File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 107, in __init__
    self.open(progress)
  File "/usr/lib/python2.7/dist-packages/apt/cache.py", line 151, in open
    self._cache = apt_pkg.Cache(progress)
SystemError: E:Encountered a section with no Package: header, E:Problem with MergeList /var/lib/apt/lists/repo.steampowered.com_steam_dists_precise_steam_i18n_Translation-en, E:The package lists or status file could not be parsed or opened.

Я попытался обновить ubuntu в надежде, что это решит проблему, но, похоже, это ничего не помогло. Проблема начала возникать после того, как в Steam возникли проблемы с обновлением. Я не знаю, актуально ли это, но вот сообщение, которое мне дали:

Steam needs to install these additional packages: 
    libgl1-mesa-dri:i386, libgl1-mesa-glx:i386
[sudo] password for montem: 
....................................................................................................................E: Encountered a section with no Package: header
E: Problem with MergeList /var/lib/apt/lists/repo.steampowered.com_steam_dists_precise_steam_i18n_Translation-en
E: The package lists or status file could not be parsed or opened.

Reading package lists... Error!
E: Encountered a section with no Package: header
E: Problem with MergeList /var/lib/apt/lists/repo.steampowered.com_steam_dists_precise_steam_i18n_Translation-en
E: The package lists or status file could not be parsed or opened.
Press return to continue: 

Как мне это исправить?