Get:1 http://security.ubuntu.com/ubuntu xenial-security InRelease [109 kB]
Get:2 http://deb.parrotsec.org/parrot stable InRelease
Get:3 http://us.archive.ubuntu.com/ubuntu xenial InRelease [247 kB]
Err:2 http://deb.parrotsec.org/parrot stable InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B56FFA946EB1660A
Err:1 http://security.ubuntu.com/ubuntu xenial-security InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32
Hit:4 http://dl.google.com/linux/chrome/deb stable InRelease
Hit:6 https://repo.skype.com/deb stable InRelease
Hit:7 https://dl.yarnpkg.com/debian stable InRelease
Hit:8 http://linux.teamviewer.com/deb stable InRelease
Hit:9 http://linux.teamviewer.com/deb preview InRelease
Hit:10 http://packages.microsoft.com/repos/vscode stable InRelease
Ign:11 http://repo.mongodb.org/apt/debian jessie/mongodb-org/3.6 InRelease
Err:3 http://us.archive.ubuntu.com/ubuntu xenial InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32
Get:13 http://repo.mongodb.org/apt/debian jessie/mongodb-org/3.6 Release [2,393 B]
Get:14 http://repo.mongodb.org/apt/debian jessie/mongodb-org/3.6 Release.gpg [801 B]
Err:14 http://repo.mongodb.org/apt/debian jessie/mongodb-org/3.6 Release.gpg
The following signatures were invalid: EXPKEYSIG 58712A2291FA4AD5 MongoDB 3.6 Release Signing Key
Hit:15 https://deb.opera.com/opera-stable stable InRelease
Err:12 http://www.getdeb.net/ubuntu xenial-getdeb InRelease
403 Forbidden [IP: 143.95.32.90 80]
Get:16 http://us.archive.ubuntu.com/ubuntu xenial-updates InRelease [109 kB]
Err:16 http://us.archive.ubuntu.com/ubuntu xenial-updates InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32
Get:17 http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease [107 kB]
Err:17 http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32
Ign:5 https://download.rethinkdb.com/apt stable InRelease
Err:18 https://download.rethinkdb.com/apt stable Release
404 Not Found [IP: 167.172.11.96 443]
Reading package lists... Done
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://deb.parrotsec.org/parrot stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY B56FFA946EB1660A
W: GPG error: http://security.ubuntu.com/ubuntu xenial-security InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32
E: The repository 'http://security.ubuntu.com/ubuntu xenial-security 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.
W: GPG error: http://us.archive.ubuntu.com/ubuntu xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32
E: The repository 'http://us.archive.ubuntu.com/ubuntu xenial 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.
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://repo.mongodb.org/apt/debian jessie/mongodb-org/3.6 Release: The following signatures were invalid: EXPKEYSIG 58712A2291FA4AD5 MongoDB 3.6 Release Signing Key
E: Failed to fetch http://archive.getdeb.net/ubuntu/dists/xenial-getdeb/InRelease 403 Forbidden [IP: 143.95.32.90 80]
E: The repository 'http://archive.getdeb.net/ubuntu xenial-getdeb 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.
W: GPG error: http://us.archive.ubuntu.com/ubuntu xenial-updates InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32
E: The repository 'http://us.archive.ubuntu.com/ubuntu xenial-updates 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.
W: GPG error: http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5 NO_PUBKEY 3B4FE6ACC0B21F32
E: The repository 'http://us.archive.ubuntu.com/ubuntu xenial-backports 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://download.rethinkdb.com/apt stable 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.
Please help to resolve this issue