Hi Mark, It seems that you have problem installing and uninstalling due to 3rd party.
Do one thing, run the following commands: 1. ps afx|grep dpkg [To check if this process is running]. 2. If there is any process, then kill with sudo killall dpkg 3. Remove the file using sudo rm /var/lib/dpkg/lock-frontend After this : 1. Go to system settings. 2. Go to Software& Updates. 3. Click on Other Software. 4. Remove all 3rd party repositories. 5. Run sudo apt-get update && sudo apt-get install -f && sudo apt-get update Then check if you are able to install or uninstall anything. ** Changed in: qt4-x11 (Ubuntu) Status: New => In Progress -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to qt4-x11 in Ubuntu. https://bugs.launchpad.net/bugs/1816047 Title: Can't install or uninstall any application Status in qt4-x11 package in Ubuntu: In Progress Bug description: I have this notification that says: ** An error occured, please run Package Manager from the right click menu or apt-get from the terminal to see what is wrong. The error message was:'Error: BrokenCount > 0'. This usually means that your installed packages have unmet dependancies ** I ran the 'sudo apt-get --qq upgrade' on the terminal and it returned: ** E: Unmet dependencies. Try 'apt --fix-broken install' with no packages (or specify a solution). ** I copy-pasted the recommendation 'apt --fix-broken install' into the terminal and got this back: ** E: Could not open lock file /var/lib/dpkg/lock-frontend - open (13: Permission denied) E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), are you root? ** I do have root privileges on my machine but beyond this point what am I meant to do as I really don't wanna mess with anything else without proper guidance. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/qt4-x11/+bug/1816047/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp