New user here. I have seen similar questions here but none of the solutions in those questions fixed these problems. When I open the app center, the "Failed to fetch updates" message pops up with the following details:
E: The repository 'http://packages.elementary.io/appcenter hera Release' does not have a Release file.
W: Updating from such a repository can't be done securely, and is therefore disabled by default.
W: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://ppa.launchpad.net/elementary-os/stable/ubuntu hera Release' does not have a Release file.
W: Updating from such a repository can't be done securely, and is therefore disabled by default.
W: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://ppa.launchpad.net/elementary-os/os-patches/ubuntu hera Release' does not have a Release file.
W: Updating from such a repository can't be done securely, and is therefore disabled by default.
W: See apt-secure(8) manpage for repository creation and user configuration details
Also when I try to install any app the "The package id's '' are not vaild" message pops up