I was trying to update the ubuntu using command sudo apt-get update. But it shows the following error;
onger signed.
E: Failed to fetch http://th.archive.ubuntu.com/ubuntu/dists/bionic/InRelease C learsigned file isn't valid, got 'NOSPLIT' (does the network require authenticat ion?)
E: Failed to fetch http://th.archive.ubuntu.com/ubuntu/dists/bionic-updates/InRe lease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require aut hentication?)
E: The repository 'http://th.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 disa bled by default.
N: See apt-secure(8) manpage for repository creation and user configuration deta ils.
E: Failed to fetch http://th.archive.ubuntu.com/ubuntu/dists/bionic-backports/In Release Clearsigned file isn't valid, got 'NOSPLIT' (does the network require a uthentication?)
E: The repository 'http://th.archive.ubuntu.com/ubuntu bionic-backports InReleas e' is no longer signed.
N: Updating from such a repository can't be done securely, and is therefore disa bled by default.
N: See apt-secure(8) manpage for repository creation and user configuration deta ils.
portal@portal-gic:/etc/apt$ clear
portal@portal-gic:/etc/apt$ sudo apt-get update
Get:1 http://security.ubuntu.com/ubuntu bionic-security InRelease
Err:1 http://security.ubuntu.com/ubuntu bionic-security InRelease
Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authenti cation?)
Get:2 http://th.archive.ubuntu.com/ubuntu bionic InRelease
Err:2 http://th.archive.ubuntu.com/ubuntu bionic InRelease
Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authenti cation?)
Get:3 http://th.archive.ubuntu.com/ubuntu bionic-updates InRelease
Err:3 http://th.archive.ubuntu.com/ubuntu bionic-updates InRelease
Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authenti cation?)
Get:4 http://th.archive.ubuntu.com/ubuntu bionic-backports InRelease
Err:4 http://th.archive.ubuntu.com/ubuntu bionic-backports InRelease
Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authenti cation?)
Reading package lists... Done
N: See apt-secure(8) manpage for repository creation and user configuration deta ils.
N: Updating from such a repository can't be done securely, and is therefore disa bled by default.
E: The repository 'http://security.ubuntu.com/ubuntu bionic-security InRelease' is no longer signed.
E: Failed to fetch http://security.ubuntu.com/ubuntu/dists/bionic-security/InRel ease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require auth entication?)
N: See apt-secure(8) manpage for repository creation and user configuration deta ils.
N: Updating from such a repository can't be done securely, and is therefore disa bled by default.
E: The repository 'http://th.archive.ubuntu.com/ubuntu bionic InRelease' is no l onger signed.
E: Failed to fetch http://th.archive.ubuntu.com/ubuntu/dists/bionic/InRelease C learsigned file isn't valid, got 'NOSPLIT' (does the network require authenticat ion?)
E: Failed to fetch http://th.archive.ubuntu.com/ubuntu/dists/bionic-updates/InRe lease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require aut hentication?)
E: The repository 'http://th.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 disa bled by default.
N: See apt-secure(8) manpage for repository creation and user configuration deta ils.
E: Failed to fetch http://th.archive.ubuntu.com/ubuntu/dists/bionic-backports/In Release Clearsigned file isn't valid, got 'NOSPLIT' (does the network require a uthentication?)
E: The repository 'http://th.archive.ubuntu.com/ubuntu bionic-backports InReleas e' is no longer signed.
N: Updating from such a repository can't be done securely, and is therefore disa bled by default.
N: See apt-secure(8) manpage for repository creation and user configuration deta ils.
could you please help me to solve this issue? thanks in advance.
