I have been using Ubuntu from time to time but not an expert. I have been looking for a fix to this problem to no avail. The Ubuntu Software Center was working fine and now suddenly it is not starting up. Initially I thought it had something to do with installing the Synaptic package manager so I removed it and tried reinstalling software center as mentioned in this question. It did not work.
Trying to run
software-center in terminal yielded the following:
2016-01-30 12:36:02,351 - softwarecenter.backend.zeitgeist_logger - WARNING - Support for Zeitgeist disabled 2016-01-30 12:36:02,415 - softwarecenter.ui.gtk3.app - INFO - setting up proxy 'None' 2016-01-30 12:36:02,474 - softwarecenter.fixme - WARNING - logs to the root logger: '('/usr/lib/python2.7/dist-packages/dbus/proxies.py', 410, '_introspect_error_handler')' 2016-01-30 12:36:02,474 - dbus.proxies - ERROR - Introspect error on com.ubuntu.sso:/com/ubuntu/sso/credentials: dbus.exceptions.DBusException: org.freedesktop.DBus.Error.Spawn.ChildExited: Process com.ubuntu.sso exited with status 1 Traceback (most recent call last): File "/usr/bin/software-center", line 130, in <module> app = SoftwareCenterAppGtk3(options, args) File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 338, in __init__ self.icons) File "/usr/share/software-center/softwarecenter/ui/gtk3/session/appmanager.py", line 66, in __init__ self.oauth_token = helper.find_oauth_token_sync() File "/usr/share/software-center/softwarecenter/backend/ubuntusso.py", line 141, in find_oauth_token_sync sso.find_credentials() File "/usr/share/software-center/softwarecenter/backend/login_impl/login_sso.py", line 74, in find_credentials self.proxy.find_credentials(self.appname, self._get_params()) File "/usr/lib/python2.7/dist-packages/dbus/proxies.py", line 70, in __call__ return self._proxy_method(*args, **keywords) File "/usr/lib/python2.7/dist-packages/dbus/proxies.py", line 145, in __call__ **keywords) File "/usr/lib/python2.7/dist-packages/dbus/connection.py", line 651, in call_blocking message, timeout) dbus.exceptions.DBusException: org.freedesktop.DBus.Error.Spawn.ChildExited: Process com.ubuntu.sso exited with status 1