I used to get the same exception. Running /usr/lib/ubuntu-sso-client /ubuntu-sso-login manually resulted in the following exception:
Traceback (most recent call last): File "/usr/lib/ubuntu-sso-client/ubuntu-sso-login", line 66, in <module> from ubuntu_sso.main import main File "/usr/lib/python2.7/dist-packages/ubuntu-sso-client/ubuntu_sso/main/__init__.py", line 96, in <module> from ubuntu_sso.main import linux as source File "/usr/lib/python2.7/dist-packages/ubuntu-sso-client/ubuntu_sso/main/linux.py", line 464, in <module> from ubuntu_sso.main import qt File "/usr/lib/python2.7/dist-packages/ubuntu-sso-client/ubuntu_sso/main/qt.py", line 39, in <module> from PyQt4 import QtCore RuntimeError: the sip module implements API v9.0 to v9.1 but the PyQt4.QtCore module requires API v8.1 It seemed to be a problem with python-sip and python-qt4. Re-installing both packages fixed it for me. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1068680 Title: Software center does not start [dbus.proxies - ERROR - Introspect error] To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-sso-client/+bug/1068680/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs