Rhythmbox will not work - launch - It is installed and used to work

Does it work ok as a different user (Make a new one if necessary).

Please open a terminal: ctrl+alt+t
Enter:
lsb_release -a
apt-cache policy rhythmbox

and run Rhythmbox from terminal:
rhythmbox

Please post complete outputs here, thanks.

It launches under another brand new user I created.

carl@carl-desktop:~$ lsb_release -a
LSB Version: core-2.0-ia32:core-2.0-noarch:core-3.0-ia32:core-3.0-noarch:core-3.1-ia32:core-3.1-noarch:core-3.2-ia32:core-3.2-noarch:core-4.0-ia32:core-4.0-noarch
Distributor ID: Ubuntu
Description: Ubuntu 11.10
Release: 11.10
Codename: oneiric
carl@carl-desktop:~$ apt-cache policy rhythmbox
rhythmbox:
  Installed: 2.90.1~20110908-0ubuntu1.3
  Candidate: 2.90.1~20110908-0ubuntu1.3
  Version table:
 *** 2.90.1~20110908-0ubuntu1.3 0
        500 http://gb.archive.ubuntu.com/ubuntu/ oneiric-updates/main i386 Packages
        100 /var/lib/dpkg/status
     2.90.1~20110908-0ubuntu1 0
        500 http://gb.archive.ubuntu.com/ubuntu/ oneiric/main i386 Packages
carl@carl-desktop:~$ rhythmbox

(rhythmbox:6604): Gtk-CRITICAL **: gtk_style_provider_get_style_property: assertion `g_type_is_a (gtk_widget_path_get_object_type (path), pspec->owner_type)' failed

(rhythmbox:6604): Gtk-CRITICAL **: gtk_style_provider_get_style_property: assertion `g_type_is_a (gtk_widget_path_get_object_type (path), pspec->owner_type)' failed

(rhythmbox:6604): Gtk-CRITICAL **: gtk_style_provider_get_style_property: assertion `g_type_is_a (gtk_widget_path_get_object_type (path), pspec->owner_type)' failed

(rhythmbox:6604): Gtk-CRITICAL **: gtk_style_provider_get_style_property: assertion `g_type_is_a (gtk_widget_path_get_object_type (path), pspec->owner_type)' failed

(rhythmbox:6604): Gtk-CRITICAL **: gtk_style_provider_get_style_property: assertion `g_type_is_a (gtk_widget_path_get_object_type (path), pspec->owner_type)' failed
Rhythmbox: could not connect to socket
Rhythmbox: No such file or directory
/usr/lib/python2.7/dist-packages/gobject/constants.py:24: Warning: g_boxed_type_register_static: assertion `g_type_from_name (name) == 0' failed
  import gobject._gobject
TypeError: metaclass conflict: the metaclass of a derived class must be a (non-strict) subclass of the metaclasses of all its bases
**
ERROR:/build/buildd/pygobject-3.0.0/gi/_gobject/pygobject.c:929:pygobject_new_full: assertion failed: (tp != NULL)
Aborted
carl@carl-desktop:~$

Run this in terminal:

sudo rm -rf /usr/share/rhythmbox/plugins/magnatune/
sudo rm -rf /usr/lib/rhythmbox/plugins/magnatune/
And try to launch Rhythmbox again!

This appears to fix it.

Found Answer on
http://askubuntu.com/questions/72175/rhythmbox-and-banshee-do-not-start-anymore