When I start software-center from the terminal, I get the following output:

2013-10-13 12:43:41,231 - softwarecenter.ui.gtk3.app - INFO - setting up proxy 'None'

2013-10-13 12:43:41,414 - softwarecenter.region - WARNING - failed to use geoclue: 'org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.Geoclue.Master was not provided by any .service files'

2013-10-13 12:43:41,618 - softwarecenter.backend.reviews - WARNING - Could not get usefulness from server, no username in config file

2013-10-13 12:43:41,621 - softwarecenter.plugin - INFO - activating plugin '<module 'webapps_activation' from '/usr/share/software-center/softwarecenter/plugins/webapps_activation.pyc'>'

2013-10-13 12:43:41,627 - softwarecenter.fixme - WARNING - logs to the root logger: '('/usr/lib/python2.7/dist-packages/gi/importer.py', 51, 'find_module')'

2013-10-13 12:43:41,627 - root - ERROR - Could not find any typelib for LaunchpadIntegration

2013-10-13 12:43:41,696 - softwarecenter.db.pkginfo_impl.aptcache - INFO - aptcache.open()

2013-10-13 12:43:43,495 - softwarecenter.fixme - WARNING - logs to the root logger: '('/usr/share/software-center/softwarecenter/utils.py', 271, 'get_title_from_html')'

2013-10-13 12:43:43,495 - root - WARNING - failed to parse: '<div style="background-color: #161513; width:1680px; height:200px;"><div style="background: url('/site_media/exhibits/2013/09/AAMFP_Leaderboard_700x200_1.jpg') top left no-repeat; width:700px; height:200px;"></div></div>' ('ascii' codec can't encode character u'xa0' in position 70: ordinal not in range(128))

2013-10-13 12:43:46,266 - softwarecenter.region - WARNING - failed to use geoclue: 'org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.Geoclue.Master was not provided by any .service files'

2013-10-13 12:43:47,452 - softwarecenter.db.utils - INFO - software-center-agent finished with status 0

When I press the 'Turn on recommendations' button, I get the following:

2013-10-13 12:48:26,466 - softwarecenter.backend.login_impl.login_sso - ERROR - _on_credentials_error for Ubuntu One: dbus.Dictionary({dbus.String(u'errtype'): dbus.String(u'GUINotAvailableError'), dbus.String(u'message'): dbus.String(u'Can not find a GUI to present to the user (tried with "('ubuntu-sso-login-qt', 'ubuntu-sso-login-qt')"). Aborting.')}, signature=dbus.Signature('ss')) ()

2013-10-13 12:48:26,467 - softwarecenter.backend.login_impl.login_sso - ERROR - _on_credentials_error for Ubuntu One: dbus.Dictionary({dbus.String(u'errtype'): dbus.String(u'GUINotAvailableError'), dbus.String(u'message'): dbus.String(u'Can not find a GUI to present to the user (tried with "('ubuntu-sso-login-qt', 'ubuntu-sso-login-qt')"). Aborting.')}, signature=dbus.Signature('ss')) ()

I'm running Xubuntu 13.10. I think I accidentally removed a wrong package.