Sudo apt-get not working in 18.04

Question

First of all i have surfed through all previous questions related to this error, but nothing worked. Below is my output of sudo apt-get update:

following an old post i ended up changing my whole sources.list file.

Get:1 http://archive.canonical.com/ubuntu xenial InRelease [3,537 B]
Err:1 http://archive.canonical.com/ubuntu xenial InRelease                     
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:2 http://archive.ubuntu.com/ubuntu xenial InRelease [3,534 B]              
Err:2 http://archive.ubuntu.com/ubuntu xenial InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:3 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [3,542 B]
Err:3 http://archive.ubuntu.com/ubuntu xenial-updates InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:4 http://archive.ubuntu.com/ubuntu xenial-backports InRelease [3,544 B]
Err:4 http://archive.ubuntu.com/ubuntu xenial-backports InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:5 http://archive.ubuntu.com/ubuntu xenial-security InRelease [3,543 B]
Err:5 http://archive.ubuntu.com/ubuntu xenial-security InRelease
  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Reading package lists... Done  
N: See apt-secure(8) manpage for repository creation and user configuration details.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
E: The repository 'http://archive.canonical.com/ubuntu xenial InRelease' is not signed.
E: Failed to fetch http://archive.canonical.com/ubuntu/dists/xenial/InRelease  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
N: See apt-secure(8) manpage for repository creation and user configuration details.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
E: The repository 'http://archive.ubuntu.com/ubuntu xenial InRelease' is not signed.
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial/InRelease  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
N: See apt-secure(8) manpage for repository creation and user configuration details.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
E: The repository 'http://archive.ubuntu.com/ubuntu xenial-updates InRelease' is not signed.
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-updates/InRelease  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-backports/InRelease  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: The repository 'http://archive.ubuntu.com/ubuntu xenial-backports InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/xenial-security/InRelease  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: The repository 'http://archive.ubuntu.com/ubuntu xenial-security InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

Solution 1

Unfortunately, the problem was in my college network, i used my phone hotspot and it worked. "AWESOME"

Solution 2

It looks like Upgrade from 16.04 to 18.04 has messed up your source list. Replace existing contents in /etc/apt/sources.list file with following lines. Backup and Remove existing other source lists in /etc/apt/sources.list.d/ to avoid any conflict.

#------------------------------------------------------------------------------#
#                            OFFICIAL UBUNTU REPOS                             #
#------------------------------------------------------------------------------#


###### Ubuntu Main Repos
deb http://in.archive.ubuntu.com/ubuntu/ bionic main restricted universe multiverse 

###### Ubuntu Update Repos
deb http://in.archive.ubuntu.com/ubuntu/ bionic-security main restricted universe multiverse 
deb http://in.archive.ubuntu.com/ubuntu/ bionic-updates main restricted universe multiverse

Run sudo apt update after it. Issue should be resolved.

Comments

[Sebastian Stark]

Please edit your post to include the apt-get output as text, not as a screenshot. Also please write in detail what exactly you tried and what didn't work.

[WiKrIe]

2 things. 1st you do not have bionic yo have xenial, 2nd check your proxy settings for apt, seams that you need this to get apt running. So checkout the post from Muru this will help you.

[R. Gurung]

i tried first command gives

[R. Gurung]

No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 18.04 LTS Release: 18.04 Codename: bionic

[pLumo]

Shame on your college network that prevents keeping you system up to date. Maybe you should report this issue to them.

[R. Gurung]

yes, it was working till yesterday.

[Fida]

I am also facing the same issue. Problem with wifi (broadband) but works with hotspot (3G). :(

[user1427944]

Dont know wht but your solution worked .. I have been stuck with this for 8 hours. any idea why but it worked ....

[R. Gurung]

@user1427944 not sure but your internet is has restrictions.

[Peter Chaula]

Same here. My LTE provider was causing a similar error. Luckily I have two routers. Switched to a different router and the problem went away.