Não é possível atualizar o Ubuntu 16.04.1 LTS de 64 bits; recebendo mensagem de erro no final (Dell DULX0035)

Question

quando atualizo e atualizo, estou recebendo o seguinte erro.

W: The repository 'http://ppa.launchpad.net/fossfreedom/packagefixes/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.
W: The repository 'http://ppa.launchpad.net/thefanclub/grive-tools/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.
W: GPG error: http://ppa.launchpad.net/boomaga/ppa/ubuntu xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY A02ACCC9C6DAEA80
W: The repository 'http://ppa.launchpad.net/boomaga/ppa/ubuntu xenial InRelease' is not signed.
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.
W: The repository 'http://ppa.launchpad.net/ubuntu-audio-dev/ppa/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.
W: GPG error: http://ppa.launchpad.net/me-davidsansome/clementine-dev/ubuntu xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 4F172854044A3B98
W: The repository 'http://ppa.launchpad.net/me-davidsansome/clementine-dev/ubuntu xenial InRelease' is not signed.
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/fossfreedom/packagefixes/ubuntu/dists/xenial/main/binary-amd64/Packages  404  Not Found
E: Failed to fetch http://ppa.launchpad.net/thefanclub/grive-tools/ubuntu/dists/xenial/main/binary-amd64/Packages  404  Not Found
E: Failed to fetch http://ppa.launchpad.net/ubuntu-audio-dev/ppa/ubuntu/dists/xenial/main/source/Sources  404  Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.

Eu verifiquei também a lista de fontes. Parece tudo bem. Mas ainda estou recebendo o erro.

    

Answer 1

Você precisa ir para System Settings - > Software & Updates . Em seguida, selecione a guia Ubuntu Software e desmarque esses itens;

http://ppa.launchpad.net/fossfreedom/packagefixes/ubuntu xenial Release
http://ppa.launchpad.net/thefanclub/grive-tools/ubuntu xenial Release
http://ppa.launchpad.net/boomaga/ppa/ubuntu xenial InRelease
http://ppa.launchpad.net/ubuntu-audio-dev/ppa/ubuntu xenial Release
http://ppa.launchpad.net/me-davidsansome/clementine-dev/ubuntu xenial InRelease

Depois de desqualificar esses itens, execute sudo apt update e você poderá atualizar seu sistema em diante.