тема оболочки gnome отключена

Может кто-нибудь помочь мне решить эту проблему.

Я новичок в Ubuntu. Дайте мне знать, какая дополнительная информация вам нужна.

xemex@ubuntu:~$ sudo apt-get install gnome-shell-extensions-user-theme
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 gnome-shell-extensions-user-theme : Depends: gnome-shell-extensions-common but it is not going to be installed
E: Unable to correct problems, you have held broken packages.