sudo apt-get update
[sudo] password for oliver:
Hit:1 http://dl.google.com/linux/chrome/deb stable InRelease
Hit:2 http://archive.canonical.com/ubuntu groovy InRelease
Hit:3 http://repository.spotify.com stable InRelease
Hit:4 http://ppa.launchpad.net/alexlarsson/flatpak/ubuntu disco InRelease
Hit:5 http://packages.microsoft.com/repos/code stable InRelease
Get:6 http://download.opensuse.org/repositories/home:/stevenpusser/xUbuntu_16.04 InRelease [1548 B]
Ign:7 http://ppa.launchpad.net/gwendal-lebihan-dev/hexchat-stable/ubuntu groovy InRelease
Hit:8 http://ppa.launchpad.net/quiterss/quiterss/ubuntu focal InRelease
Hit:9 https://deb.opera.com/opera-stable stable InRelease
Hit:10 http://de.archive.ubuntu.com/ubuntu groovy InRelease
Hit:11 https://brave-browser-apt-release.s3.brave.com stable InRelease
Hit:12 http://ppa.launchpad.net/vincent-vandevyvre/vvv/ubuntu eoan InRelease
Hit:13 https://repo.skype.com/deb stable InRelease
Get:14 http://de.archive.ubuntu.com/ubuntu groovy-updates InRelease [115 kB]
Hit:15 https://ftp.gajim.org/debian unstable InRelease
Err:16 http://ppa.launchpad.net/gwendal-lebihan-dev/hexchat-stable/ubuntu groovy Release
404 Not Found [IP: 91.189.95.85 80]
Get:17 http://de.archive.ubuntu.com/ubuntu groovy-security InRelease [110 kB]
Get:18 http://de.archive.ubuntu.com/ubuntu groovy-backports InRelease [101 kB]
Err:6 http://download.opensuse.org/repositories/home:/stevenpusser/xUbuntu_16.04 InRelease
The following signatures were invalid: EXPKEYSIG 0FAD31CA8719FCE4 home:stevenpusser OBS Project <home:stevenpusser@build.opensuse.org>
Get:19 http://de.archive.ubuntu.com/ubuntu groovy-updates/main amd64 Packages [434 kB]
Get:20 http://de.archive.ubuntu.com/ubuntu groovy-updates/main i386 Packages [188 kB]
Get:21 http://de.archive.ubuntu.com/ubuntu groovy-updates/main Translation-en [108 kB]
Get:22 http://de.archive.ubuntu.com/ubuntu groovy-updates/main amd64 DEP-11 Metadata [40.6 kB]
Get:23 http://de.archive.ubuntu.com/ubuntu groovy-updates/universe amd64 Packages [161 kB]
Get:24 http://de.archive.ubuntu.com/ubuntu groovy-updates/universe i386 Packages [86.3 kB]
Get:25 http://de.archive.ubuntu.com/ubuntu groovy-updates/universe Translation-en [63.0 kB]
Get:26 http://de.archive.ubuntu.com/ubuntu groovy-updates/universe amd64 DEP-11 Metadata [103 kB]
Get:27 http://de.archive.ubuntu.com/ubuntu groovy-updates/multiverse amd64 DEP-11 Metadata [2468 B]
Get:28 http://de.archive.ubuntu.com/ubuntu groovy-security/main amd64 DEP-11 Metadata [4692 B]
Get:29 http://de.archive.ubuntu.com/ubuntu groovy-security/universe amd64 DEP-11 Metadata [4548 B]
Get:30 http://de.archive.ubuntu.com/ubuntu groovy-backports/universe amd64 DEP-11 Metadata [600 B]
Reading package lists... Done
E: The repository 'http://ppa.launchpad.net/gwendal-lebihan-dev/hexchat-stable/ubuntu groovy 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.
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://download.opensuse.org/repositories/home:/stevenpusser/xUbuntu_16.04 InRelease: The following signatures were invalid: EXPKEYSIG 0FAD31CA8719FCE4 home:stevenpusser OBS Project <home:stevenpusser@build.opensuse.org>