Обновление Ubuntu 16.04 дает ошибку сегментации

выполнение sudo apt-get update дает следующую ошибку:

** (appstreamcli:5640): WARNING **: No origin found for file packages.microsoft.com_repos_vscode_dists_stable_main_dep11_Components-amd64.yml.gz
Segmentation fault (core dumped)
Reading package lists... Done
W: http://archive.canonical.com/dists/lucid/InRelease: Signature by key 630239CC130E1A7FD81A27B140976EAF437D05B5 uses weak digest algorithm (SHA1)
W: The repository 'http://ppa.launchpad.net/werner-jaeger/ppa-werner-vpn/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/werner-jaeger/ppa-werner-vpn/ubuntu/dists/xenial/main/binary-amd64/Packages  404  Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.
E: Problem executing scripts APT::Update::Post-Invoke-Success 'if /usr/bin/test -w /var/cache/app-info -a -e /usr/bin/appstreamcli; then appstreamcli refresh > /dev/null; fi'

Я пытался удалить cache/*.bin и изменить lists, но ничего не изменилось. sudo apt-get upgrade Однако выполняется без каких-либо ошибок. Буду признателен за любые предложения.