How to Fix Unmet Dependencies Error on Ubuntu

Error The following packages have unmet dependencies has plagued Ubuntu users for a while now, and there are more and more sightings of the error on various versions of Ubuntu. The APT package management system is easy to use, but in some occasions, such as when you’re mixing in third-party dependencies, you might get this error from apt-get.

This happens when you try to install something with the apt system via a terminal, and the installation fails with no obvious problem whatsoever. This issue isn’t limited to any one particular program, but it might happen with quite a few of them. This is because the issue lies in the apt system, and not in the program you’re installing.

There are fortunately quite a few solutions for this, some of which are easier to do, and others more difficult, but if you follow the instructions in the methods below, you will get rid of the error in no time.

Note: Before proceeding with any of the methods, it is advisable that you back up configurations files such as  so you can revert back any changes in case something goes wrong. This is done by using the following steps:

1. Press simultaneously the Alt, Ctrl and T on your keyboard to open a Terminal.
2. Type in  and press Enter.
3. When the previous command finishes running, type in sudo cp /var/lib/dpkg/status /var/lib/dpkg/status.original and press Enter again.

Method 1: Use the -f parameter

This is the easiest one to try, and only requires adding two more letters to the command that you’re typing. Instead of using sudo apt-get install PACKAGENAME, where PACKAGENAME is the package you’re trying to install with the apt system, use sudo apt-get install -f. The -f parameter will attempt to correct a system which has broken dependencies, after which you’ll be able to install the package in question.

1. Open a Terminal by pressing Ctrl, Alt and T simultaneously on your keyboard.
2. Type in sudo apt-get install -f and press Enter to execute it.
3. Once it’s done, type in sudo dpkg –configure -a, press Enter to run it, and run the command from step 2 once more.

Method 2: Use Aptitude

Aptitude is an alternative of apt-get which you can use as a higher-level package manager. You can use it to try and install your package with it, instead of apt-get, but first you need to install aptitude.

1. Press simultaneously the Ctrl, Alt, and T keys on your keyboard to open a
2. Type in sudo apt-get install aptitude and press Enter to execute the command.
3. Type in sudo aptitude install PACKAGENAME, where PACKAGENAME is the package you’re installing, and press Enter to execute it. This will try to install the package via aptitude instead of apt-get, which should potentially fix the unmet dependencies issue.

Method 3: Make sure that the restricted and universe repositories are enabled and try a better server

1. Press simultaneously Alt and F2 on your computer, type in software-properties-gtk and press
2. In the Ubuntu Software tab, make sure that all the repositories (main, universe, restricted, multiverse) are enabled.
3. Click the list of servers where it says Download from, and choose
4. Click Select Best Server.
5. Press Alt, Ctrl and T simultaneously to open a Terminal, and type in sudo apt-get update, then press Once it’s done running, try installing the software again.

Method 4: Clean the package database

A corrupted package database is a potential cause for unmet dependencies, as well as packages not installing properly. However, cleaning the package database can fix this, and you can do it with two commands, which I will explain below. First of all, however, press Ctrl, Alt and T to open a Terminal, and don’t forget to hit Enter after the command in order to run it.

1. sudo apt-get clean will clean the local repository from all the retrieved package files (.deb). It will remove everything except the lock files from /var/cache/apt/archives, and /var/cache/apt/archives/partial/.
2. sudo apt-get autoclean will also clean up the retrieved files, but unlike the previous command, this one only removes packages that you can no longer download and are pretty much useless.

Method 5: Eliminate any held packages

Held packages are actually held because there are dependency problems and conflicts which apt can’t solve. Eliminating such packages means that there won’t be any such conflicts, and may consequently fix your issue.

1. Open a Terminal by pressing Ctrl, Alt and T
2. Type in sudo apt-get -u dist-upgrade and press If there are any held packages, it will show them, and it is yours to eliminate them.
3. First try running

sudo apt-get -o Debug::pkgProblemResolver=yes dist-upgrade

and see if it fixes the issue. If it exits with X not upgraded at the end, where X is the number of held packages, you will need to delete them one by one.

4. To remove a held package, use sudo apt-get remove –dry-run PACKAGENAME (PACKAGENAME is the package you’re trying to remove). The –dry-run parameter makes sure you are informed of whatever happens next. When you’ve removed all packages, try installing the one that caused the problem in the first place, and see what happens.

Method 6: Purge/Remove/Disable PPAs

Personal Package Archives are repositories that are hosted on the Launchpad, and are used to upgrade or install packages that aren’t usually available in the official repositories of Ubuntu. They’re most commonly a cause of unmet dependencies, especially when they’re used to upgrade an existing package from the Ubuntu repository. You can either disable, remove or purge them.

Disable means that packages installed from that PPA will no longer get updates.

1. Press simultaneously Alt and F2, and run software-properties-gtk.
2. From the Other Software tab, you will find two lines for every PPA, where one is for the source, and another for the compiled package. To disable a PPA, you should uncheck both lines.

Purge means that all packages in the selected PPA will be downgraded to the version in the official repositories, and will also disable the PPA. To install PPA Purge, you could use sudo apt-get install ppa-purge, but considering that the apt is broken, you should use this command in the Terminal (Alt, Ctrl and T simultaneously, then Enter to run):

mkdir ppa-purge && cd ppa-purge && wget http://mirror.pnl.gov/ubuntu/pool/universe/p/ppa-purge/ppa-purge_0.2.8+bzr56_all.deb && wget http://mirror.pnl.gov/ubuntu//pool/main/a/aptitude/aptitude_0.6.6-1ubuntu1_i386.deb && sudo dpkg -i ./*.deb

Next, run sudo ppa-purge ppa:someppa/ppa in order to purge the selected PPA. However, since PPA Purge still doesn’t remove a PPA, you can use the commands below to remove the PPA. Ignore the first one if your intentions don’t include removing the installed package.

1. sudo apt-get autoremove –purge PACKAGENAME
2. sudo add-apt-repository –remove ppa:someppa/ppa
3. sudo apt-get autoclean

You should be able to install the necessary package afterwards.