애플리케이션을 업데이트하려고 할 때 기본 운영 체제 오류가 발생했습니다.

기본 OS Hera 5.1(터미널 또는 AppCenter를 통해)에서 애플리케이션을 업데이트할 수 없습니다.

AppCenter로 이동하여 앱/시스템을 업데이트하려고 하면 다음 오류가 표시됩니다.

E: The repository 'http://ppa.launchpad.net/mpstark/elementary-tweaks-daily/ubuntu bionic 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: GPG error: https://download.01.org/gfx/ubuntu/14.04/main saucy InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY FFACA3F86663559C
E: The repository 'https://download.01.org/gfx/ubuntu/14.04/main saucy InRelease' is not signed.
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: https://download.01.org/gfx/ubuntu/14.04/main saucy InRelease is not (yet) available (The following signatures couldn't be verified because the public key is not available: NO_PUBKEY FFACA3F86663559C)
E: The repository 'http://ppa.launchpad.net/pinta-maintainers/pinta-stable/ubuntu bionic 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

sudo apt-get upgrade이전에 일반적으로 사용했던 앱을 업데이트할 수 있었지만 지금은 업데이트하면 이 오류가 발생하고 실제로 업데이트되는 것은 없습니다.

W: GPG error: https://download.01.org/gfx/ubuntu/14.04/main saucy InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY FFACA3F86663559C
E: The repository 'https://download.01.org/gfx/ubuntu/14.04/main saucy InRelease' is not signed.
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.
E: The repository 'http://ppa.launchpad.net/mpstark/elementary-tweaks-daily/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.
E: The repository 'http://ppa.launchpad.net/pinta-maintainers/pinta-stable/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.

이 오류를 어떻게 해결할 수 있나요?