小编AGV*_*GVG的帖子

2 个多月后我打开了 Ubuntu 16.04，现在我收到安装任何软件包的错误（我尝试安装redshift软件包（夜间模式））。

ERROR E: Unable to locate package apt_pkg

我尝试更新 Ubuntu，然后收到错误消息：

W: The repository 'http://ppa.launchpad.net/jonathonf/python-3.6/ubuntu xenial Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: Failed to fetch http://ppa.launchpad.net/jonathonf/python-3.6/ubuntu/dists/xenial/main/binary-amd64/Packages  404  Not Found [IP: 91.189.95.83 80]
E: Some index files failed to download. They have been ignored, or old ones used …