sudo apt-get update
Hit:1 Index of /ubuntu cosmic InRelease
Get:2 Index of /ubuntu cosmic-updates InRelease [83.2 kB]
Get:3 Index of /ubuntu cosmic-security InRelease [83.2 kB]
Ign:4 Index of /ubilinux/up/ubuntu cosmic InRelease
Get:5 Index of /ubuntu cosmic-backports InRelease [74.6 kB]
Hit:6 http://linux.teamviewer.com/deb stable InRelease
Err:7 Index of /ubilinux/up/ubuntu cosmic Release
404 Not Found [IP: 91.189.95.83 80]
Reading package lists... Done
E: The repository 'Index of /ubilinux/up/ubuntu cosmic 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.