Запуск "apt-get update" возвращает ошибку " apt-secure (8)"

У меня есть Ubuntu Game Pack, и я пытаюсь использовать sudo apt-get update и это повторение ошибки

W: https://download.01.org/gfx/ubuntu/16.04/main/dists/xenial/InRelease: Signature by key 09D6EF97BFB38E916EF060E756A3DEF863961D39 uses weak digest algorithm (SHA1)
W: GPG error: http://deb.playonlinux.com trusty InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 73F0D6E88E3D6C3A
W: The repository 'http://deb.playonlinux.com trusty 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: GPG error: http://download.opensuse.org/repositories/home:/strycore/xUbuntu_16.04 ./ Release: The following signatures were invalid: KEYEXPIRED 1484261108
W: The repository 'http://download.opensuse.org/repositories/home:/strycore/xUbuntu_16.04 ./ Release' 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.

Как я могу решить это?