I just started using Ubuntu so please give me an explained answer.  I was trying to install macbuntu theme in my Ubuntu 16.10. I did the first step which was   sudo add-apt-repository ppa:noobslab/macbuntu   This step worked fine. Next when I did,  sudo apt-get update   I got the error  W: The repository 'http://ppa.launchpad.net/docky-core/stable/ubuntu yakkety Release' does not have a Release file. N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use. N: See apt-secure(8) manpage for repository creation and user configuration details. E: Failed to fetch http://ppa.launchpad.net/docky-core/stable/ubuntu/dists/yakkety/main/binary-amd64/Packages  404  Not Found E: Some index files failed to download. They have been ignored, or old ones used instead.   These are just the last few lines which gives the error.  How do I solve this?  EDIT : This is the contents of the sources.list.d directory       docky-core-ubuntu-stable-yakkety.list     docky-core-ubuntu-stable-yakkety.list.save     noobslab-ubuntu-macbuntu-yakkety.list     noobslab-ubuntu-macbuntu-yakkety.list.save     webupd8team-ubuntu-java-yakkety.list     webupd8team-ubuntu-java-yakkety.list.save     webupd8team-ubuntu-sublime-text-3-yakkety.list     webupd8team-ubuntu-sublime-text-3-yakkety.list.save   Output of lsb_release -a command       No LSB modules are available.     Distributor ID: Ubuntu     Description:    Ubuntu 16.10     Release:    16.10     Codename:   yakkety
831
PPA seems to be constantly offline. Whenever I use sudo apt-get update, this error is shown:  W: Failed to fetch http://ppa.launchpad.net/ 404  Not Found   How do I fix these errors?
71967
I've noticed that running apt-get update recently has resulted in quite a few ppa's returning "403 Forbidden".  In and effort to clean them up I had a look:  W: Failed to fetch http://ppa.launchpad.net/gnome3-team/gnome3/ubuntu/dists/raring/main/binary-amd64/Packages  403  Forbidden  W: Failed to fetch http://ppa.launchpad.net/gnome3-team/gnome3/ubuntu/dists/raring/main/binary-i386/Packages  403  Forbidden  E: Some index files failed to download. They have been ignored, or old ones used instead.   The strange things is, if I copy these URLs into my browser I can access the files just fine.  Why would apt-get report "403 Forbidden" if they're still accessible?  I tried re-adding the ppa through add-apt-repository which downloads the signing key again, and it still reported "403 Forbidden".
82983
when trying to update package listings via apt update or apt-get update I receive the following error:  E: Failed to fetch http://lt.archive.ubuntu.com/ubuntu/dists/xenial/universe/dep11/Components-amd64.yml.gz  Hash Sum mismatch E: Failed to fetch http://lt.archive.ubuntu.com/ubuntu/dists/xenial/universe/dep11/icons-64x64.tar  Writing more data than expected (7468511 &gt; 7467723) [IP: 193.219.61.87 80]   Is this somehow related to localised package distributor or is me all along? I am running beta2 release, that I've successfully installed and updated (without any error prompts) yesterday. Previously I used a 14.04 derivative which also did not bring up any errors. What can be the reason for this error?  EDIT: to duplicate markers, the topic name tackles a different problem rather than the hash sum problem, which is being referenced.
16444
The server version of Ubuntu does not have the  command. How can I add a  (PPA) to the server without this command?
33256
I can get Ubuntu mainline kernels from  - is there a way to add it to my repository list the same as regular Launchpad PPAs?
47429
I’m running Ubuntu 14.04. When I run:   sudo add-apt-repository ppa:ubuntu-wine/ppa   I get the following error:  sudo: add-apt-repository: command not found   I tried to run  sudo apt-get install software-properties-common   but it shows:  software-properties-common is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.
122549
Setting up keys for a local repository on a new ubuntu 20.10 virtual machine, I got a message that apt-key add was deprecated and I should read the apt-key(8) man page. The apt-key(8) man page is a collection of words strung together, but if it contains information I can't winkle it out. Can anyone tell me what, exactly, I should type on my terminal instead of: apt-key add name-of-file The command does apparently still work after honking at me, so I was able to proceed, but would like to know what I'll need to do in the future.
73996
Where can I get the old repositories for Ubuntu versions? In my case, it's 9.04 Jaunty?   I found all the official repositories and their mirrors have been removed. I am wondering where I can get the repository list for this version?
74992
After a reinstall of Ubuntu 12.04 ,it's impossible to install commercial games, e.g Oil Rush. It gives this error:  Failed to fetch https://private-ppa.launchpad.net/commercial-ppa-uploaders/oilrush/ubuntu/dists/oneiric/main/binary-amd64/Packages  The requested URL returned error: 401 Failed to fetch https://private-ppa.launchpad.net/commercial-ppa-uploaders/oilrush/ubuntu/dists/oneiric/main/binary-i386/Packages  The requested URL returned error: 401 Some index files failed to download. They have been ignored, or old ones used instead.   I bought these games in 11.10, but I installed these games in 12.04 before... How can I solve this problem?
85552
I am performing an update and its failing on the following:  The repository 'http://ppa.launchpad.net/izx/askubuntu/ubuntu xenial Release' does not have a Release file..   Running a local Ubuntu server 16.04
86410
I am unable to install Macaulay2. I am following the guideline given in the website . I have added the repository in the sources list (see the attached screenshot). I have installed the key from the link above. Now when I search for the package with apt-cache search macaylay2 I get nothing.   I have also looked at the answer to  but I don't think that will work either, please help.
22654
I am using Ubuntu 14.04. How to install and configure the latest version of  on Ubuntu.  I would like to know how to install it from PPA and from source.
71790
I'm trying to find what packages I have installed from a repository using terminal commands.  I found a post somewhere saying I could use aptitude search "?origin (&lt;repository&gt;) ?installed", but I couldn't get it working. I tried searching for a packages that came from ppa:ubuntu-wine/ppa and got nothing with these:  aptitude search "?origin (http://ppa.launchpad.net/ubuntu-wine/ppa/ubuntu/) ?installed" aptitude search "?origin (http://ppa.launchpad.net/ubuntu-wine/ppa/ubuntu/) ?installed" aptitude search "?origin (http://ppa.launchpad.net/ubuntu-wine/ppa/ubuntu/ raring/main) ?installed"   It would be nice if I could get something that works with PPAs.
81990
I've been trying to get , but it's only available through Quantal, and I'm running Raring. Is there a way to force-install a PPA from a previous release? I tried manually downloading all the packages and running sudo dpkg -i but I get lots of errors about dependencies, some of which don't look like they can be resolved. Am I stuck with having to compile vim myself?
50553
I use Ubuntu Studio 16.04 LTS, 64 bit, into 3 desktop PC (Intel i5 and i7) and 4 laptops (Intel Pentium). All with 8 GB of RAM.  Since about a week ago, I've been getting the following message each time I try to update/upgrade the system:  https://download.01.org/gfx/ubuntu/16.04/main xenial InRelease" has no Public Key. It isn't safe to use this kind of repository.   I tried to remove that repository (which I don't remember adding) with the terminal command:  sudo add-apt-repository -r &lt;repository to  remove&gt;   But, even though the system seems to perform that action, the repository is used next time I type:  sudo apt-get update   This repository isn't visible in Synaptic Software Manager and/or Ubuntu Software Center.  How can I fix it?
108324
I'm running Ubuntu 16.04 LTS on a Macbook 2015 (not Pro). Laptop keyboard and trackpad are not working (except power button). I have installed   from GitHub, but it still do not work.  I have no idea what else to try or commands to run to to make changes.  Hope someone managed to make Ubuntu (or an alternative distro work on a Macbook).  EDIT  Here is print of cat /etc/initramfs-tools/modules  # List of modules that you want to include in your initramfs. # They will be loaded at boot time in the order below. # # Syntax:  module_name [args ...] # # You must run update-initramfs(8) to effect this change. # # Examples: # # raid1 # sd_mod  # applespi applespi spi_pxa2xx_platform spi_pxa2xx_pci  # applespi applespi spi_pxa2xx_platform intel_lpss_pci   I think there are two groups of applespi, because I tried both installations methods listed in on GitHub for the macbook12-spi-driver (link above).
31146
In Ubuntu one can add a repository via following command -   sudo add-apt-repository ppa:yannubuntu/boot-repair   As Ubuntu is based on Debian code base, I was expecting that the same would work in Debian too, but it doesn't.   What is the reason for this? Is there some other shell command I can use to achieve the same?   Note:  I know I can edit /etc/apt/sources.list, but I want to achieve this from the shell. I also want to know why the same command won't work when the code base is the same.