Problem with Ubuntu Software Center--can't install anything

Question

About 3 weeks ago I downloaded Ubuntu 12.04 and I've been running it since then. Initially everything worked great, but about 10 days ago the Ubuntu Software Center quit working (I previously used it with no problems).Now, I can open it up and find programs, but when I click the Install button for one of them, nothing happens. This issue seems to be specific to the Software Center--I can still use apt-get from the command line with no problems.

I've tried removing and reinstalling the Software Center, and I've tried running it from the terminal using sudo software-center (in case there was some issue with permissions). When I use the terminal, upon starting up software-center a long error message is printed to the terminal (yes, an apparently identical traceback is printed twice):

2013-08-25 12:38:50,829 - softwarecenter.ui.gtk3.app - INFO - setting up proxy 'None'
2013-08-25 12:38:50,833 - softwarecenter.db.database - INFO - open() database: path=None use_axi=True use_agent=True
2013-08-25 12:38:51,079 - softwarecenter.backend.reviews - WARNING - Could not get usefulness from server, no username in config file
2013-08-25 12:38:51,178 - softwarecenter.ui.gtk3.app - INFO - show_available_packages: search_text is '', app is None.
2013-08-25 12:38:51,181 - softwarecenter.db.pkginfo_impl.aptcache - INFO - aptcache.open()
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/dbus/connection.py", line 607, in msg_reply_handler
*message.get_args_list()))
  File "/usr/lib/python2.7/dist-packages/dbus/bus.py", line 69, in error_cb
callback('')
  File "/usr/share/software-center/softwarecenter/backend/installbackend_impl/aptd.py", line 153, in _register_active_transactions_watch
apt_daemon = client.get_aptdaemon(bus=bus)
  File "/usr/lib/python2.7/dist-packages/aptdaemon/client.py", line 1696, in get_aptdaemon
False),
  File "/usr/lib/python2.7/dist-packages/dbus/bus.py", line 241, in get_object
follow_name_owner_changes=follow_name_owner_changes)
  File "/usr/lib/python2.7/dist-packages/dbus/proxies.py", line 248, in __init__
self._named_service = conn.activate_name_owner(bus_name)
  File "/usr/lib/python2.7/dist-packages/dbus/bus.py", line 180, in activate_name_owner
self.start_service_by_name(bus_name)
  File "/usr/lib/python2.7/dist-packages/dbus/bus.py", line 278, in start_service_by_name
'su', (bus_name, flags)))
  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: Launch helper exited with unknown return code 1
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/dbus/connection.py", line 607, in msg_reply_handler
*message.get_args_list()))
  File "/usr/lib/python2.7/dist-packages/dbus/bus.py", line 69, in error_cb
callback('')
  File "/usr/share/software-center/softwarecenter/backend/installbackend_impl/aptd.py", line 153, in _register_active_transactions_watch
apt_daemon = client.get_aptdaemon(bus=bus)
  File "/usr/lib/python2.7/dist-packages/aptdaemon/client.py", line 1696, in get_aptdaemon
False),
  File "/usr/lib/python2.7/dist-packages/dbus/bus.py", line 241, in get_object
follow_name_owner_changes=follow_name_owner_changes)
  File "/usr/lib/python2.7/dist-packages/dbus/proxies.py", line 248, in __init__
self._named_service = conn.activate_name_owner(bus_name)
  File "/usr/lib/python2.7/dist-packages/dbus/bus.py", line 180, in activate_name_owner
self.start_service_by_name(bus_name)
  File "/usr/lib/python2.7/dist-packages/dbus/bus.py", line 278, in start_service_by_name
'su', (bus_name, flags)))
  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: Launch helper exited with unknown return code 1
2013-08-25 12:38:53,215 - softwarecenter.ui.gtk3.widgets.exhibits - WARNING - download failed: '<class 'gi._glib.GError'>', 'Operation not supported'

Any suggestions?

EDIT: After searching some more, I found this bug report: https://bugs.launchpad.net/ubuntu/+source/software-center/+bug/1085425 It describes symptoms similar to mine, and I found that when I ran

/usr/lib/ubuntu-sso-client/ubuntu-sso-login

as described there, I got a series of error messages, ending with:

ImportError: No module named pkg_resources

I then found this stackoverflow thread: https://stackoverflow.com/questions/7446187/no-module-named-pkg-resources where I was able to use the top comment to re-install setuptools, which fixed my problem.

Answer 1

Try these:

Open terminal (CTRL+ALT+T) and execute following commands:

sudo apt-get autoclean
sudo apt-get autoremove
sudo apt-get --purge remove
sudo apt-get -f install

Above commands will try to fix broken packages if any and also install required library files if missed accidentally.

If still it does not work then only thing you can do is to use some other Package Manager, best is Synaptic Package Manager. You can add/remove/update/fix-broken packages very easily using it. As you told that Ubuntu Software Center is not able to install packages, then browse packages in it and install the same using Synaptic Package Manager.

Install it using this command:

sudo apt-get install synaptic

I hope you'll like this package manager.

Answer 2

In a terminal, run the following commands.

sudo apt-get check
sudo apt-get update
sudo apt-get upgrade
rm -r ~/.cache/software-center
sudo dpkg --configure -a
sudo apt-get clean

Answer 3

I think your server is the problem

Try selecting a different one

• search for Synaptic Package Manager in the Dash
• select Settings > repositories > Ubuntu Software
• select a new server under download from

See this page in the Ubuntu help wiki for more detail: Repositories help.