无法更新Ubuntu

Question

我对Ubuntu非常陌生，只是在尝试使用update命令时出现了这个错误。有人能帮我解决这个问题吗？

谢谢!

~$ sudo apt-get update
[sudo] password for alastair: 
Ign:1 http://ppa.launchpad.net/nvbn-rm/ppa/ubuntu bionic InRelease
Hit:2 http://security.ubuntu.com/ubuntu bionic-security InRelease              
Hit:3 http://ppa.launchpad.net/webupd8team/y-ppa-manager/ubuntu bionic InRelease
Err:4 http://ppa.launchpad.net/nvbn-rm/ppa/ubuntu bionic Release               
  404  Not Found [IP: 91.189.95.83 80]
Hit:5 http://gb.archive.ubuntu.com/ubuntu bionic InRelease                     
Hit:6 http://gb.archive.ubuntu.com/ubuntu bionic-updates InRelease       
Hit:7 http://gb.archive.ubuntu.com/ubuntu bionic-backports InRelease     
Hit:8 http://archive.canonical.com/ubuntu bionic InRelease
Reading package lists... Done                      
E: The repository 'http://ppa.launchpad.net/nvbn-rm/ppa/ubuntu bionic Release' does not have a Release file.
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.

Answer 1

根据这个链接：软件和更新：如何移除存储库？，我已经删除了C1中的启动板链接，这似乎已经在目前起作用了。