%20focal%20Release'%20n%C3%A3o%20possui%20um%20arquivo%20Release%22%3F%20.png)
$ sudo apt update
E: The repository 'cdrom://Ubuntu 20.04.2.0 LTS _Focal Fossa_ - Release amd64 (20210209.1) focal 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.
Responder1
Abra Software & Updates, na aba Ubuntu Software, desmarque Cdrom com Ubuntu 20.04 'Focal Fossa' em Instalável a partir de CD-ROM/DVD