我在软件和更新中选择了“选择最佳服务器”选项 ->“Ubuntu 软件”->“下载自”->“其他”。单击“关闭”后，系统返回
The information about available software is out-of-date
我单击“重新加载”，然后显示
Failed to download repository information
在“详细信息”下，它会显示一个带有以下错误消息的小窗口：
E:Failed to fetch http://ppa.launchpad.net/samoilov-lex/aftl-stable/ubuntu/dists/artful/InRelease 403 Forbidden [IP: 185.125.190.52 80], E:The repository 'http://ppa.launchpad.net/samoilov-lex/aftl-stable/ubuntu artful InRelease' is not signed., W:Updating from such a repository can't be done securely, and is therefore disabled by default., W:See apt-secure(8) manpage for repository creation and user configuration details., W:Skipping acquire of configured file 'main/binary-i386/Packages' as repository 'https://swupdate.openvpn.net/community/openvpn3/repos bionic InRelease' doesn't support architecture 'i386', W:An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://apt.releases.hashicorp.com bionic InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY AA16FCBCA621E701, W:GPG error: http://developer.download.nvidia.com/compute/cuda/repos/ubuntu1804/x86_64 InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A4B469963BF863CC, E:The repository 'http://developer.download.nvidia.com/compute/cuda/repos/ubuntu1804/x86_64 InRelease' is no longer signed., W:Updating from such a repository can't be done securely, and is therefore disabled by default., W:See apt-secure(8) manpage for repository creation and user configuration details., W:An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://dl.yarnpkg.com/debian stable InRelease: The following signatures were invalid: EXPKEYSIG 23E7166788B63E1E Yarn Packaging <[email protected]>, W:An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://packages.cloud.google.com/apt kubernetes-xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B53DC80D13EDEF05, W:An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://build.openvpn.net/debian/openvpn/stable bionic InRelease: The following signatures were invalid: EXPKEYSIG 8E6DA8B4E158C569 Samuli Seppänen (OpenVPN Technologies, Inc) <[email protected]>
我需要做什么才能从 Ubuntu 18.04 升级到 Ubuntu 20.04？
编辑：
我能够使用 升级到 20.04.6，sudo apt dist-upgrade然后使用sudo do-release-upgrade。但 UI 升级路径有问题。