Ubuntu workaround: "Apt-get 404 Not Found Package Repository" issue when executing the ' sudo apt-get update ' command

Ubuntu Solution: When executing sudo apt-get update or sudo apt-get install command is appearing "Apt-get 404 Not Found Package Repository" issue and "E : Some index files failed to download They have been ignored, or old ones used "issue

When you execute the sudo apt-get update command, if you encounter the following problem:

W:the repository ' http://ppa.launchpad.net/ackondro/tibesti/ubuntu xenial release ' does not have a release file.
N:data from such a repository can ' t being authenticated and is therefore potentially to use.
N:see apt-secure (8) Manpage for repository creation and User Configuration details.
e:failed to fetch http://ppa.launchpad.net/ackondro/tibesti/ubuntu/dists/xenial/main/binary-amd64/Packages  404 Not  Found
e:some index files failed to download. They have been ignored, or old ones used.
E:could not get Lock/var/lib/dpkg/lock-open (11:resource temporarily unavailable)
e:unable to lock the ADMINISTR ation directory (/var/lib/dpkg/), is another process using it?

Or

W:the repository ' http://ppa.launchpad.net/ackondro/tibesti/ubuntu xenial release ' does not have a release file.
N:data from such a repository can ' t being authenticated and is therefore potentially to use.
N:see apt-secure (8) Manpage for repository creation and User Configuration details.
e:failed to fetch http://ppa.launchpad.net/ackondro/tibesti/ubuntu/dists/xenial/main/binary-amd64/Packages  404 Not  Found
e:some index files failed to download. They have been ignored, or old ones used.

Solving Method

First, we'll back up a copy of the/etc/apt/sources.list file that is now problematic. (Just a good habit)

sudo cp/etc/apt/sources.list/etc/apt/sources.list_backup

Note: The/etc/apt/sources.list file contains the Web site of the software source required by the Linux system.

Next, we rewrite a/etc/apt/sources.list file:

sudo gedit/etc/apt/sources.list

After you copy and paste the following template content into the/etc/apt/sources.list file, save it: (we use Ubuntu is 16.04)

deb http://cn.archive.ubuntu.com/ubuntu/xenial main restricted universe Multiverse Deb http ://cn.archive.ubuntu.com/ubuntu/xenial-security main restricted universe multiverse Deb Http://cn.archive.ubuntu.com /ubuntu/xenial-updates main restricted universe multiverse Deb Http://cn.archive.ubuntu.com/ubuntu/xenial-backports Main restricted Universe Multiverse # #测试版源 Deb http://cn.archive.ubuntu.com/ubuntu/xenial-proposed main restricted Universe Multiverse # source DEB-SRC http://cn.archive.ubuntu.com/ubuntu/xenial main restricted universe multiverse deb-src H Ttp://cn.archive.ubuntu.com/ubuntu/xenial-security main restricted universe multiverse deb-src http:// Cn.archive.ubuntu.com/ubuntu/xenial-updates main restricted universe multiverse deb-src http://cn.archive.ubuntu.com /ubuntu/xenial-backports main restricted Universe Multiverse # #测试版源 DEB-SRC http://cn.archive.ubuntu.com/ubuntu/ xenial-proposed main restricted universe multiverse 

For other versions, replace the xenial with the version code:
16.04
Xenial (Template details)
15.10
Willy (Template details)
14.04
Trusty (Template details)
12.04
Precise (template details)

Now, then execute:

sudo apt-get update

Now there is no "apt-get 404 Not Found Package Repository Errors" problem.

Summary:
This problem, the solution is simple, but for beginners, it is a tentacle problem.

The reason for this problem is: the previous/etc/apt/sources.list path of the software source update site is outdated, need to update the new site.

Unable to connect to cn.archive.ubuntu.com:http: [112.124.140.210 80]

If you have such a mistake, your network is broken, check the network connection situation.

Reference website:

How to fix Ubuntu/debian apt-get 404 Not Found Package Repository (Errors, Saucy, Raring, Quantal, oneiric ...)
https://smyl.es/ how-to-fix-ubuntudebian-apt-get-404-not-found-package-repository-errors-saucy-raring-quantal-oneiric-natty/
Ubuntu Apt-get Unable to fetch packages
http://stackoverflow.com/questions/30316812/ Ubuntu-apt-get-unable-to-fetch-packages
Source list
Http://wiki.ubuntu.org.cn/%E6%BA%90%E5%88%97%E8%A1%A8