几个月来，我在软件更新程序和终端上使用 sudo apt update 或 sudo apt-get update 更新内容时一直遇到错误。我尝试了不少技巧，但到目前为止没有任何变化。
这是我的错误信息：
Ign:1 cdrom://Ubuntu 20.04.3 LTS _Focal Fossa_ - Release amd64 (20210819) focal InRelease
Err:2 cdrom://Ubuntu 20.04.3 LTS _Focal Fossa_ - Release amd64 (20210819) focal Release
Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
Hit:4 http://security.ubuntu.com/ubuntu focal-security InRelease
Hit:6 https://repo.steampowered.com/steam stable InRelease
Get:3 http://mirror.genesisadaptive.com/ubuntu focal InRelease
Get:5 http://mirror.genesisadaptive.com/ubuntu focal-updates InRelease
Get:7 http://mirror.genesisadaptive.com/ubuntu focal-security InRelease
Err:3 http://mirror.genesisadaptive.com/ubuntu focal InRelease
Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Err:5 http://mirror.genesisadaptive.com/ubuntu focal-updates InRelease
Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Err:7 http://mirror.genesisadaptive.com/ubuntu focal-security InRelease
Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
Hit:8 http://archive.ubuntu.com/ubuntu focal 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 'cdrom://Ubuntu 20.04.3 LTS _Focal Fossa_ - Release amd64 (20210819) focal 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://mirror.genesisadaptive.com/ubuntu focal InRelease' is no longer signed.
E: Failed to fetch http://mirror.genesisadaptive.com/ubuntu/dists/focal/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: Failed to fetch http://mirror.genesisadaptive.com/ubuntu/dists/focal-updates/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: The repository 'http://mirror.genesisadaptive.com/ubuntu focal-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://mirror.genesisadaptive.com/ubuntu/dists/focal-security/InRelease Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: The repository 'http://mirror.genesisadaptive.com/ubuntu focal-security 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.
我不知道这是否正常，但它让我很烦