Update manager generates 404 error while attempting update. Will not update [duplicate]

Automated removal

skip to the bottom of this answer for a scripted way to remove offending software-sources for all ubuntu versions prior to Ubuntu 15.04

What are 404 errors

The 404 or Not Found error message is a HTTP standard response code indicating that the client was able to communicate with the server, but the server could not find what was requested.

The web site hosting server will typically generate "404 - Page Not Found" web page, when users attempts to follow a broken or dead link.

What are the causes of these errors in update-manager

Typically, three main areas cause these errors in update-manager

1. A user has just upgraded and has re-enabled a PPA software-source that no longer exists
2. A user has manually typed in a new software source incorrectly
3. A PPA was added, but the maintainer has subsequently deleted some/all of the PPA

where are these software-sources

PPAs typically are saved in one of two locations

1. /etc/apt/sources.list
2. in an appropriately named file with a .list file-extension in /etc/apt/sources.list.d/ for example webupd8team-jupiter-natty.list

This list file typically contains:

deb http://ppa.launchpad.net/webupd8team/jupiter/ubuntu oneiric main
# deb-src http://ppa.launchpad.net/webupd8team/jupiter/ubuntu oneiric main

Note a # at the front of a line of text means that it is commented out and is not checked by the package manager.

How to eliminate these errors

Typically, if you run sudo apt-get update from a terminal or click the details button in Update Manager after hitting the refresh button you will see errors such as:

If the error is due to a PPA - usually unticking the similarly named PPA with the URL shown in the error message will resolve this.

If the 404 error was due to an additional repository that has been added to /etc/apt/sources.list then its easier to add # character to the start of the line to comment out the offending repository i.e.

gksu gedit /etc/apt/sources.list

More info

Here is a bug report on the update manager to solve this problem:

• https://bugs.launchpad.net/ubuntu/+source/update-manager/+bug/1049046

If you are getting these problems without PPAs, check out this question:

• How can I fix a 404 Error using the Ubuntu archives?
• Repositories/Ubuntu - Community Ubuntu Documentation - Removing & Disabling Repositories

Automated Removal of 404 Not found PPA's through script

This is a script to remove automatically all the 404 Not found PPA's.Copy the below code and paste it into a file and name it as ppa-remove.

#!/bin/bash
sudo rm /tmp/update.txt; tput setaf 6; echo "Initializing.. Please Wait" 
sudo apt-get update >> /tmp/update.txt 2>&1; awk '( /W:/ && /launchpad/ && /404/ ) { print substr($5,26) }' /tmp/update.txt > /tmp/awk.txt; awk -F '/' '{ print $1"/"$2 }' /tmp/awk.txt > /tmp/awk1.txt; sort -u /tmp/awk1.txt > /tmp/awk2.txt
tput sgr0
if [ -s /tmp/awk2.txt ]
then
  tput setaf 1
  printf "PPA's going to be removed\n%s\n" "$(cat /tmp/awk2.txt)"
  tput sgr0
  while read -r line; do echo "sudo add-apt-repository -r ppa:$line"; done < /tmp/awk2.txt > out
  bash out
else
  tput setaf 1
  echo "No PPA's to be removed"
  tput sgr0
fi

Give execute permission to the script

sudo chmod +x ppa-remove

Copy and paste the ppa-remove file into /usr/bin directory.So that you can access it from anywhere.

Usage

sudo ppa-remove

Script Description

[ -f /tmp/update.txt ] && sudo rm /tmp/update.txt; tput setaf 6; echo "Initializing.. Please Wait" || echo "No update file"

tput setaf 6 command turns the terminal text colour into green.And then it displays "Initializing ..Please Wait" in green colour.

sudo apt-get update >> /tmp/update.txt 2>&1; awk '( /W:/ && /launchpad/ && /404/ ) { print substr($5,26) }' /tmp/update.txt > /tmp/awk.txt; awk -F '/' '{ print $1"/"$2 }' /tmp/awk.txt > /tmp/awk1.txt; uniq /tmp/awk1.txt > /tmp/awk2.txt

1. sudo apt-get update >> /tmp/update.txt 2>&1;

   Both stdout and stderr of the command sudo apt-get update are written to the file /tmp/update.txt

2. awk '( /W:/ && /launchpad/ && /404/ ) { print substr($5,26) }' /tmp/update.txt > /tmp/awk.txt; awk -F '/' '{ print $1"/"$2 }' /tmp/awk.txt > /tmp/awk1.txt;

Awk searches for the line which consists of W:,launchpad,404 in the /tmp/update.txt file.If it found that then in that line it displays(stdout) all the letters starting from the 26th location in column5.This standard output was redirected(written) to the /tmp/awk.txtfile.

For example:

W: Failed to fetch http://ppa.launchpad.net/pitti/postgresql/ubuntu/dists/saucy/main/binary-i386/Packages  404  Not Found

5th coloumn - http://ppa.launchpad.net/pitti/postgresql/ubuntu/dists/saucy/main/binary-i386/Packages

in that 5th column start from 26th character- pitti/postgresql/ubuntu/dists/saucy/main/binary-i386/Packages

This above line was stored into /tmp/awk.txt file.Now the next command,

awk -F '/' '{ print $1"/"$2 }' /tmp/awk.txt > /tmp/awk1.txt;  

awk findout out the column1 and column2 with the delimiter / where the column1 and column2 are concatenated by /from the /tmp/awk.txt file and then redirects(written) the stdout to /tmp/awk1.txt file.

Now /tmp/awk1.txt file contains pitti/postgresql line.

uniq /tmp/awk1.txt > /tmp/awk2.txt

If there are two same lines, unique command displays(stdout) single line only.That single line was written to /tmp/awk2.txt Finally /tmp/awk2.txt consists of unique PPA names.

tput sgr0

This command changes the colour of terminal text into white.

Finally if conditional statements will executes. if [ -s /tmp/awk2.txt ] check for the contents of /tmp/awk2.txt file presents or not.If yes, then it takes the first line from /tmp/awk2.txt and executes sudo add-apt-repository -r ppa:$line command.It continues upto to the last line.

If no, it means there is no contents.So it says "No PPA's to be removed".

Screenshots

You are getting these errors because your PPA repositories don't provide packages for your distribution of Ubuntu (ie; quantal).

Look at the following screenshots:

ppa:petrakis/wdt-main

ppa:screenlets/ppa

You can see that the directory for quantal is missing and hence you are getting 404 Not Found Error Messages.

To get rid of these messages you have to remove these PPA repositories from your system. Follow this question on how to remove PPAs:

• See the section called "How to eliminate these errors" in this answer.
• Or, How can PPAs be removed?

How to investigate this and come to this conclusion?

These are the error messages you receive for wdt-main PPA:

W:Failed to fetch http://ppa.launchpad.net/petrakis/wdt-main/ubuntu/dists/quantal/main/source/Sources  404  Not Found
, W:Failed to fetch http://ppa.launchpad.net/petrakis/wdt-main/ubuntu/dists/quantal/main/binary-amd64/Packages  404  Not Found
, W:Failed to fetch http://ppa.launchpad.net/petrakis/wdt-main/ubuntu/dists/quantal/main/binary-i386/Packages  404  Not Found

Open your browser tab and open the link which gives 404 Not Found Errors. In this case http://ppa.launchpad.net/petrakis/ and go deeper as per the link which gives errors. You would be able to see what the actual problem is.