Can't move or resize windows after installing ubuntu-desktop with aptitude

Question

I have Ubuntu 16.04:

root@ubuntu:~# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 16.04.5 LTS
Release:    16.04
Codename:   xenial

root@ubuntu:~# uname -a
Linux ubuntu 4.15.0-45-generic #48~16.04.1-Ubuntu SMP Tue Jan 29 18:03:48 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

I had problems with the GUI desktop that wasn't loading so I installed it with aptitude:

aptitude install ubuntu-desktop 

But after the GUI is loaded there is only the desktop without the bar and all the menus and I can't move\resize the windows.

I tried to reinstall ubuntu-desktop with apt-get but it failed:

root@ubuntu:~# apt-get install --reinstall ubuntu-desktop
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:
 ubuntu-desktop : Depends: unity but it is not going to be installed
                  Recommends: network-manager-gnome but it is not going to be installed
                  Recommends: snapd but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

The current version installed:

root@ubuntu:~# apt-cache policy ubuntu-desktop
ubuntu-desktop:
  Installed: (none)
  Candidate: 1.361
  Version table:
     1.361 500
        500 http://us.archive.ubuntu.com/ubuntu xenial/main amd64 Packages

Answer 1

I restored the /etc/apt/source.list file by this answer.

This is the source.list in my case:

#------------------------------------------------------------------------------#
#                            OFFICIAL UBUNTU REPOS                             #
#------------------------------------------------------------------------------#

###### Ubuntu Main Repos
deb http://il.archive.ubuntu.com/ubuntu/ xenial main restricted universe multiverse 
deb-src http://il.archive.ubuntu.com/ubuntu/ xenial main restricted universe multiverse 

###### Ubuntu Update Repos
deb http://il.archive.ubuntu.com/ubuntu/ xenial-security main restricted universe multiverse 
deb http://il.archive.ubuntu.com/ubuntu/ xenial-updates main restricted universe multiverse 
deb-src http://il.archive.ubuntu.com/ubuntu/ xenial-security main restricted universe multiverse 
deb-src http://il.archive.ubuntu.com/ubuntu/ xenial-updates main restricted universe multiverse 

###### Ubuntu Partner Repo
deb http://archive.canonical.com/ubuntu xenial partner
deb-src http://archive.canonical.com/ubuntu xenial partner

deb http://us.archive.ubuntu.com/ubuntu/ xenial main universe restricted multiverse
deb http://security.ubuntu.com/ubuntu/ xenial-security multiverse universe restricted main
deb http://us.archive.ubuntu.com/ubuntu/ xenial-updates multiverse universe restricted main

After running apt-get update I was able to run apt-get install --reinstall ubuntu-desktop and then rebooted the machine.
Now everything is back to normal.