System Info :
morpheous@ZEUS:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 18.04.3 LTS
Release: 18.04
Codename: bionic
Clearing System THEN updating:
morpheous@ZEUS:~$ sudo rm -rf /var/lib/apt/lists/*
morpheous@ZEUS:~$ sudo apt clean
morpheous@ZEUS:~$ sudo apt update
Get:3 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu bionic InRelease [15.9 kB]
Ign:5 http://dl.google.com/linux/chrome/deb stable InRelease
Get:6 http://ppa.launchpad.net/freecad-maintainers/freecad-stable/ubuntu bionic InRelease [15.4 kB]
Ign:7 https://deb.nodesource.com/node_10.x bionic InRelease
Get:1 http://gb.archive.ubuntu.com/ubuntu bionic InRelease
Err:8 https://deb.nodesource.com/node_10.x bionic Release
Could not handshake: Error in the pull function. [IP: 13.224.132.5 443]
Err:1 http://gb.archive.ubuntu.com/ubuntu bionic InRelease
Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:2 http://gb.archive.ubuntu.com/ubuntu bionic-updates InRelease
Err:2 http://gb.archive.ubuntu.com/ubuntu bionic-updates InRelease
Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:9 http://linux.teamviewer.com/deb stable InRelease [9,388 B]
Get:4 http://gb.archive.ubuntu.com/ubuntu bionic-backports InRelease
Err:4 http://gb.archive.ubuntu.com/ubuntu bionic-backports InRelease
Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Get:10 http://dl.google.com/linux/chrome/deb stable Release [943 B]
Get:11 http://packages.microsoft.com/repos/vscode stable InRelease [3,182 B]
Get:12 http://dl.google.com/linux/chrome/deb stable Release.gpg [819 B]
Get:13 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu bionic/main i386 Packages [26.8 kB]
Get:14 http://security.ubuntu.com/ubuntu bionic-security InRelease [88.7 kB]
Get:15 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu bionic/main amd64 Packages [26.8 kB]
Get:16 http://ppa.launchpad.net/deadsnakes/ppa/ubuntu bionic/main Translation-en [6,552 B]
Get:17 http://ppa.launchpad.net/freecad-maintainers/freecad-stable/ubuntu bionic/main i386 Packages [17.0 kB]
Get:18 http://ppa.launchpad.net/freecad-maintainers/freecad-stable/ubuntu bionic/main amd64 Packages [17.0 kB]
Get:19 http://linux.teamviewer.com/deb stable/main i386 Packages [3,264 B]
Get:20 http://linux.teamviewer.com/deb stable/main amd64 Packages [3,548 B]
Get:21 http://ppa.launchpad.net/freecad-maintainers/freecad-stable/ubuntu bionic/main Translation-en [6,756 B]
Get:22 https://download.sublimetext.com apt/stable/ InRelease [2,562 B]
Get:23 http://packages.microsoft.com/repos/vscode stable/main amd64 Packages [142 kB]
Get:24 http://dl.google.com/linux/chrome/deb stable/main amd64 Packages [1,104 B]
Get:25 https://download.sublimetext.com apt/stable/ Packages [1,014 B]
Get:26 http://security.ubuntu.com/ubuntu bionic-security/main i386 Packages [373 kB]
Get:27 http://security.ubuntu.com/ubuntu bionic-security/main amd64 Packages [516 kB]
Get:28 http://security.ubuntu.com/ubuntu bionic-security/main Translation-en [173 kB]
Get:29 http://security.ubuntu.com/ubuntu bionic-security/main amd64 DEP-11 Metadata [26.3 kB]
Get:30 http://security.ubuntu.com/ubuntu bionic-security/main DEP-11 48x48 Icons [14.6 kB]
Get:31 http://security.ubuntu.com/ubuntu bionic-security/main DEP-11 64x64 Icons [37.8 kB]
Get:32 http://security.ubuntu.com/ubuntu bionic-security/restricted amd64 Packages [7,648 B]
Get:33 http://security.ubuntu.com/ubuntu bionic-security/restricted i386 Packages [4,280 B]
Get:34 http://security.ubuntu.com/ubuntu bionic-security/restricted Translation-en [3,064 B]
Get:35 http://security.ubuntu.com/ubuntu bionic-security/universe i386 Packages [591 kB]
Get:36 http://security.ubuntu.com/ubuntu bionic-security/universe amd64 Packages [607 kB]
Get:37 http://security.ubuntu.com/ubuntu bionic-security/universe Translation-en [202 kB]
Get:38 http://security.ubuntu.com/ubuntu bionic-security/universe amd64 DEP-11 Metadata [42.1 kB]
Get:39 http://security.ubuntu.com/ubuntu bionic-security/universe DEP-11 48x48 Icons [16.4 kB]
Get:40 http://security.ubuntu.com/ubuntu bionic-security/universe DEP-11 64x64 Icons [111 kB]
Get:41 http://security.ubuntu.com/ubuntu bionic-security/multiverse i386 Packages [4,152 B]
Get:42 http://security.ubuntu.com/ubuntu bionic-security/multiverse amd64 Packages [4,904 B]
Get:43 http://security.ubuntu.com/ubuntu bionic-security/multiverse Translation-en [2,396 B]
Get:44 http://security.ubuntu.com/ubuntu bionic-security/multiverse amd64 DEP-11 Metadata [2,464 B]
Get:45 http://security.ubuntu.com/ubuntu bionic-security/multiverse DEP-11 48x48 Icons [29 B]
Get:46 http://security.ubuntu.com/ubuntu bionic-security/multiverse DEP-11 64x64 Icons [2,638 B]
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 'https://deb.nodesource.com/node_10.x bionic Release' does not have a Release file.
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://gb.archive.ubuntu.com/ubuntu bionic InRelease' is not signed.
E: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/bionic/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: Failed to fetch http://gb.archive.ubuntu.com/ubuntu/dists/bionic-updates/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: The repository 'http://gb.archive.ubuntu.com/ubuntu bionic-updates 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://gb.archive.ubuntu.com/ubuntu/dists/bionic-backports/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: The repository 'http://gb.archive.ubuntu.com/ubuntu bionic-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.
How do I fix these errors, so I can update my system without errors?
I see 2 errors.
choose download from main server.
shows you where
comes from. remove it. And then run