Bdtyktl

im extremely new to ubuntu, and since yesterday i've been unable to update directly from the software center. i open terminal and try sudo apt-get update, but i get the error "

E: Malformed entry 52 in list file /etc/apt/sources.list (Component)

E: The list of sources could not be read.

E: Malformed entry 52 in list file /etc/apt/sources.list (Component)

E: The list of sources could not be read

Contents of sources.list:

deb cdrom:[Ubuntu 18.04.1 LTS _Bionic Beaver_ - Release amd64 (20180725)]/ bionic main restricted



# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to

# newer versions of the distribution.

deb http://us.archive.ubuntu.com/ubuntu/ bionic main restricted

# deb-src http://us.archive.ubuntu.com/ubuntu/ bionic main restricted



## Major bug fix updates produced after the final release of the

## distribution.

deb http://us.archive.ubuntu.com/ubuntu/ bionic-updates main restricted

# deb-src http://us.archive.ubuntu.com/ubuntu/ bionic-updates main restricted



## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu

## team. Also, please note that software in universe WILL NOT receive any

## review or updates from the Ubuntu security team.

deb http://us.archive.ubuntu.com/ubuntu/ bionic universe

# deb-src http://us.archive.ubuntu.com/ubuntu/ bionic universe

deb http://us.archive.ubuntu.com/ubuntu/ bionic-updates universe

# deb-src http://us.archive.ubuntu.com/ubuntu/ bionic-updates universe



## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu 

## team, and may not be under a free licence. Please satisfy yourself as to 

## your rights to use the software. Also, please note that software in 

## multiverse WILL NOT receive any review or updates from the Ubuntu

## security team.

deb http://us.archive.ubuntu.com/ubuntu/ bionic multiverse

# deb-src http://us.archive.ubuntu.com/ubuntu/ bionic multiverse

deb http://us.archive.ubuntu.com/ubuntu/ bionic-updates multiverse

# deb-src http://us.archive.ubuntu.com/ubuntu/ bionic-updates multiverse



## N.B. software from this repository may not have been tested as

## extensively as that contained in the main release, although it includes

## newer versions of some applications which may provide useful features.

## Also, please note that software in backports WILL NOT receive any review

## or updates from the Ubuntu security team.

deb http://us.archive.ubuntu.com/ubuntu/ bionic-backports main restricted universe multiverse

# deb-src http://us.archive.ubuntu.com/ubuntu/ bionic-backports main restricted universe multiverse



## Uncomment the following two lines to add software from Canonical's

## 'partner' repository.

## This software is not part of Ubuntu, but is offered by Canonical and the

:

Answer by SirCharlo on How do I restore the default repositories? was my saving grace.

Several lines appear to have gone missing, and a ":" has appeared where it shouldn't be.

• In a terminal, enter sudo nano /etc/apt/sources.list and enter your password.


• 
  

  Remove the ":" and replace it by:

  
  
  

  deb http://security.ubuntu.com/ubuntu bionic-security main restricted 
  
  deb http://security.ubuntu.com/ubuntu bionic-security universe
  
  deb http://security.ubuntu.com/ubuntu bionic-security multiverse
  
  

  
  



• Press Ctrl + O to save the file, and Ctrl + X to exit from nano.



• Do sudo apt update.

It should work from here on.