Ubuntu 18.04 The repository is no longer signed

[sunnixx]

Hi

I am getting this error when ever I am trying to
sudo apt-get update


Get:1 http://pk.archive.ubuntu.com/ubuntu bionic InRelease [253 B]
Err:1 http://pk.archive.ubuntu.com/ubuntu bionic InRelease
Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Hit:2 http://security.ubuntu.com/ubuntu bionic-security InRelease
Hit:3 http://ppa.launchpad.net/webupd8team/java/ubuntu bionic InRelease
Ign:4 http://dl.google.com/linux/chrome/deb stable InRelease
Get:5 http://pk.archive.ubuntu.com/ubuntu bionic-updates InRelease [261 B]
Err:5 http://pk.archive.ubuntu.com/ubuntu bionic-updates InRelease
Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Hit:6 https://download.mono-project.com/repo/ubuntu stable-bionic InRelease
Get:7 http://pk.archive.ubuntu.com/ubuntu bionic-backports InRelease [263 B]
Err:7 http://pk.archive.ubuntu.com/ubuntu bionic-backports InRelease
Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Hit:8 http://packages.microsoft.com/repos/vscode stable InRelease
Hit:9 https://dl.yarnpkg.com/debian stable InRelease
Hit:10 http://dl.google.com/linux/chrome/deb stable Release
Hit:12 https://packages.microsoft.com/ubuntu/18.04/prod bionic InRelease
Hit:13 https://packagecloud.io/slacktechnologies/slack/debian jessie InRelease
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://pk.archive.ubuntu.com/ubuntu bionic InRelease' is no longer signed.
E: Failed to fetch http://pk.archive.ubuntu.com/ubuntu/dists/bionic/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require
authentication?)
E: Failed to fetch http://pk.archive.ubuntu.com/ubuntu/dists/bionic-updates/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network
require authentication?)
E: The repository 'http://pk.archive.ubuntu.com/ubuntu bionic-updates InRelease' is no longer 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://pk.archive.ubuntu.com/ubuntu/dists/bionic-backports/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the networ
k require authentication?)
E: The repository 'http://pk.archive.ubuntu.com/ubuntu bionic-backports InRelease' is no longer 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.



Any help would be really appreciated ?

[TheFu]

If you visit http://pk.archive.ubuntu.com/ubuntu with a normal browser, what happens?

[sunnixx]

I can access it properly and even
wget returns me with success