There are many possible reasons why Ubuntu Software (a.k.a. gnome-software) is not working for you. I was having issues with it myself.
Firstly, since you started but were not able to complete installs, you probably have an install queue that you need to clear.
Make sure Ubuntu Software (gnome-software) is not running. Before making any changes, you want to backup the gnome-software folder that lives in your home directory, which holds the install queue. In Terminal or a CLI:
cp -r ~/.local/share/gnome-software ~/.local/share/gnome-software-BAK
Clear the install queue
Reopen Ubuntu Software (either from launcher or by typing
gnome-software into the command line)
If the above doesn't work, you could also try removing your home folder's gnome-software directory altogether. Quit Ubuntu Software, then enter:
rm -r ~/.local/share/gnome-software
Restart Ubuntu Software. If that did not help, You can always undo the removal of the gnome-software folder and restore the backup:
rm -r ~/.local/share/gnome-software && mv ~/.local/share/gnome-software-BAK ~/.local/share/gnome-software
You could also be having problems because you need to run an upgrade.
Your sources list might be causing issues for you. My problems with Ubuntu Software were resolved by fully removing PPA's that I thought I had gotten rid of using
add-apt-repository --remove, which did not get rid of their .list files in
/etc/apt/sources.list.d/, nor did it get rid of their keyrings in
/etc/apt/trusted.gpg.d/. If the software you're trying to install is from a PPA, you could still try cleaning out other PPA's, as these may be slowing down Ubuntu Software. There are known issues with the PPA associated with google-chrome-stable, for example.
Edit the list (
/etc/apt/sources.list) itself. It's much speedier to do it completely from command line:
sudo nano /etc/apt/sources.list then
sudo apt-get update. You can also do this in the Software and Updates GUI (run from launcher or open in command line with
software-properties-gtk), but it seems to take so much longer to do the updating step when I use the GUI. I can add steps for doing it this way if you want, though.
If you already know the names of the PPA's you want to remove then you can get rid of them one by one using the command:
sudo add-apt-repository --remove ppa:<repo>/<subdirectory>. Note: There's also
ppa-purge, which I didn't want to use because it downgrades packages associated with the PPA to versions available in repositories, and I wasn't sure if this would affect the programs I had installed, as the programs themselves were not the problem.
sources.list, you may find (like I did) that old PPA's are still showing up in
/etc/apt/sources.list.d (a directory containing
.list files of each PPA), and their keyrings were still in
You can check this yourself by entering the command:
ls -lR /etc/apt/ | grep -v '~'
Then you can get a list of the .list files in sources.list.d and remove them one by one:
sudo rm -i /etc/apt/sources.list.d/<PPAName>.list
sudo apt-get update
To remove the keys:
sudo apt-key list
sudo apt-key del <KEY_ID>
sudo apt-get update
After this, Ubuntu Software was actually functioning, hope this helps you!
There's also the possibility you need to do a "deeper" version of sudo apt-get upgrade:
sudo apt-get dist-upgrade