Невозможно обновить Ubuntu 17.04 до 18.08 [дубликат]

После попытки обновления с 17.04 до 18.0 появляется это сообщение:

E: The repository 'http://ppa.launchpad.net/jonathonf/vlc/ubuntu zesty Release' does not have a Release file.
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: Target Sources (main/source/Sources) is configured multiple times in /etc/apt/sources.list.d/videolan-ubuntu-master-daily-zesty.list:2 and /etc/apt/sources.list.d/videolan-ubuntu-master-daily-zesty.list:3
E: The repository 'http://ppa.launchpad.net/videolan/stable-daily/ubuntu zesty Release' does not have a Release file.
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.
E: The repository 'http://archive.ubuntu.com/ubuntu zesty Release' does not have a Release file.
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.
E: The repository 'http://archive.ubuntu.com/ubuntu zesty-updates Release' does not have a Release file.   
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.
E: The repository 'http://archive.ubuntu.com/ubuntu zesty-backports Release' does not have a Release file.  
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.
E: The repository 'http://archive.ubuntu.com/ubuntu zesty-security Release' does not have a Release file.
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.
E: The repository 'http://archive.ubuntu.com/ubuntu zesty-proposed Release' does not have a Release file.

У меня нетбук eMachines E350, процессор Intel Atom и 2 ГБ оперативной памяти. Обязательно ли загружать ISO-образ 18.04?