Не удалось открыть Software Center или Update Manager

Я - текущий рабочий Xubuntu 12.04 64 бита. Я заметил, что не могу открыть центр программного обеспечения или обновить менеджера.

Когда я пытаюсь открыть Update Manager, он сообщает об этом a problem occurred while checking for updates.

После запуска центра программного обеспечения сообщение об ошибке появится и скажет мне

Failed to execute command "/usr/bin/software-center %u". 
Failed to execute child process "/usr/bin/software-center" (No such file or directory)

Выполнение sudo Кв. - добирается, обновление показывает еще больше проблем

david@david-laptop:~$ sudo apt-get upgrade
[sudo] password for david: 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
4 not fully installed or removed.
Need to get 0 B/689 kB of archives.
After this operation, 0 B of additional disk space will be used.
Do you want to continue [Y/n]? y
(Reading database ... 575296 files and directories currently installed.)
Preparing to replace python-software-properties 0.82.7.7 (using .../python-software-properties_0.82.7.7_all.deb) ...
/var/lib/dpkg/info/python-software-properties.prerm: 6: /var/lib/dpkg/info/python-software-properties.prerm: pyclean: not found
dpkg: warning: subprocess old pre-removal script returned error exit status 127
dpkg - trying script from the new package instead ...
/var/lib/dpkg/tmp.ci/prerm: 6: /var/lib/dpkg/tmp.ci/prerm: pyclean: not found
dpkg: error processing /var/cache/apt/archives/python-software-properties_0.82.7.7_all.deb (--unpack):
 subprocess new pre-removal script returned error exit status 127
/var/lib/dpkg/info/python-software-properties.postinst: 6: /var/lib/dpkg/info/python-software-properties.postinst: pycompile: not found
dpkg: error while cleaning up:
 subprocess installed post-installation script returned error exit status 127
Preparing to replace software-center 5.2.10 (using .../software-center_5.2.10_all.deb) ...
/var/lib/dpkg/info/software-center.prerm: 6: /var/lib/dpkg/info/software-center.prerm: pyclean: not found
dpkg: warning: subprocess old pre-removal script returned error exit status 127
dpkg - trying script from the new package instead ...
/var/lib/dpkg/tmp.ci/prerm: 6: /var/lib/dpkg/tmp.ci/prerm: pyclean: not found
dpkg: error processing /var/cache/apt/archives/software-center_5.2.10_all.deb (--unpack):
 subprocess new pre-removal script returned error exit status 127
/var/lib/dpkg/info/software-center.postinst: 8: /var/lib/dpkg/info/software-center.postinst: pycompile: not found
dpkg: error while cleaning up:
 subprocess installed post-installation script returned error exit status 127
Preparing to replace software-properties-common 0.82.7.7 (using .../software-properties-common_0.82.7.7_all.deb) ...
/var/lib/dpkg/info/software-properties-common.prerm: 6: /var/lib/dpkg/info/software-properties-common.prerm: pyclean: not found
dpkg: warning: subprocess old pre-removal script returned error exit status 127
dpkg - trying script from the new package instead ...
/var/lib/dpkg/tmp.ci/prerm: 6: /var/lib/dpkg/tmp.ci/prerm: pyclean: not found
dpkg: error processing /var/cache/apt/archives/software-properties-common_0.82.7.7_all.deb (--unpack):
 subprocess new pre-removal script returned error exit status 127
/var/lib/dpkg/info/software-properties-common.postinst: 6: /var/lib/dpkg/info/software-properties-common.postinst: pycompile: not found
dpkg: error while cleaning up:
 subprocess installed post-installation script returned error exit status 127
Preparing to replace software-properties-gtk 0.82.7.7 (using .../software-properties-gtk_0.82.7.7_all.deb) ...
/var/lib/dpkg/info/software-properties-gtk.prerm: 6: /var/lib/dpkg/info/software-properties-gtk.prerm: pyclean: not found
dpkg: warning: subprocess old pre-removal script returned error exit status 127
dpkg - trying script from the new package instead ...
/var/lib/dpkg/tmp.ci/prerm: 6: /var/lib/dpkg/tmp.ci/prerm: pyclean: not found
dpkg: error processing /var/cache/apt/archives/software-properties-gtk_0.82.7.7_all.deb (--unpack):
 subprocess new pre-removal script returned error exit status 127
No apport report written because MaxReports is reached already
                                                              /var/lib/dpkg/info/software-properties-gtk.postinst: 11: /var/lib/dpkg/info/software-properties-gtk.postinst: pycompile: not found
dpkg: error while cleaning up:
 subprocess installed post-installation script returned error exit status 127
Errors were encountered while processing:
 /var/cache/apt/archives/python-software-properties_0.82.7.7_all.deb
 /var/cache/apt/archives/software-center_5.2.10_all.deb
 /var/cache/apt/archives/software-properties-common_0.82.7.7_all.deb
 /var/cache/apt/archives/software-properties-gtk_0.82.7.7_all.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)`

Я действительно потерян здесь, и любая справка ценится.

Заранее спасибо тому, кто бы ни может помочь мне