Fix apt update E: Repository no longer has a Release file

Reproduce and read the full error

Run apt update and capture the full output. The error always includes the exact URL of the broken repository, which you need for the next steps.

sudo apt update

Look for a line similar to this in the output.

Err:3 http://ppa.launchpad.net/example/ppa/ubuntu jammy Release
  404  Not Found
E: The repository 'http://ppa.launchpad.net/example/ppa/ubuntu jammy Release' no longer has a Release file.

Understand why this happens

There are four common causes. A PPA maintainer deleted the PPA or stopped building for your release. A third-party repository shut down or moved domains. Your Ubuntu or Debian release reached end of life and was removed from the regular mirrors, since EOL releases only remain on archive servers. A mirror is mid-sync and temporarily missing the Release file, which is rare and usually resolves on its own within an hour.

Check if your release is end of life

Ubuntu standard releases are supported for 9 months, LTS releases for 5 years with optional ESM. Debian releases are supported until the next stable plus one year under LTS. If your release is past its support window, every one of its original mirror entries will fail, not just one.

cat /etc/os-release

Compare the VERSION_CODENAME value against the current support table.

Locate the problematic entry in sources.list

Repository entries live in two places on modern Ubuntu and Debian: the legacy sources.list file and individual .list or .sources files under sources.list.d. Search both for the URL from the error message.

grep -rn "ppa.launchpad.net/example" /etc/apt/sources.list /etc/apt/sources.list.d/

On Ubuntu 24.04 you may also find entries in the newer deb822 format with a .sources extension.

cat /etc/apt/sources.list.d/ubuntu.sources

List all configured repositories for a full audit

Before editing anything, get a complete picture of every active source so you do not miss a second broken entry.

grep -rhE '^deb |^Types: deb' /etc/apt/sources.list /etc/apt/sources.list.d/ 2>/dev/null

Note the filename of each entry that references the broken URL. You will edit or remove these files in the next step.

Disable or remove the stale repository safely

Do not delete working repositories blindly. Comment out or remove only the specific line that matches the failing URL, keeping a backup first.

sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak

If the broken entry is a PPA in its own file under sources.list.d, remove that file directly.

sudo rm /etc/apt/sources.list.d/example-ppa-ubuntu-jammy.list

If the entry is a single line inside sources.list, comment it out instead of deleting the whole file.

sudo sed -i 's|^deb http://ppa.launchpad.net/example/ppa/ubuntu|#deb http://ppa.launchpad.net/example/ppa/ubuntu|' /etc/apt/sources.list

Fix EOL Ubuntu releases by switching to old-releases.ubuntu.com

When an Ubuntu release goes end of life, packages move from the regular mirror network to a permanent archive. You need to repoint every archive.ubuntu.com and security.ubuntu.com entry to old-releases.ubuntu.com.

sudo sed -i 's|http://archive.ubuntu.com/ubuntu|http://old-releases.ubuntu.com/ubuntu|g; s|http://security.ubuntu.com/ubuntu|http://old-releases.ubuntu.com/ubuntu|g; s|http://.*.archive.ubuntu.com/ubuntu|http://old-releases.ubuntu.com/ubuntu|g' /etc/apt/sources.list

Verify the change applied correctly before moving on.

grep deb /etc/apt/sources.list

Fix EOL Debian releases by switching to archive.debian.org

Debian follows the same pattern through its own permanent archive. Replace deb.debian.org and security.debian.org with archive.debian.org, and drop the -updates and security suites since the archive only keeps the final frozen state.

sudo sed -i 's|deb.debian.org|archive.debian.org|g; s|security.debian.org|archive.debian.org|g' /etc/apt/sources.list

Remove lines referencing buster-updates or buster/updates since the archive does not serve update suites separately.

sudo sed -i '/buster-updates/d; /buster\/updates/d' /etc/apt/sources.list

Re-add correct GPG keys with signed-by

If apt also reports NO_PUBKEY or a signature verification failure alongside the Release file error, the repository's GPG key is missing or was added using the deprecated apt-key method. Modern apt expects a keyring file referenced explicitly with signed-by.

curl -fsSL https://example.com/repo/gpg-key.asc | sudo gpg --dearmor -o /usr/share/keyrings/example-repo.gpg

Then reference that keyring directly in the repository entry instead of relying on the global keyring.

deb [signed-by=/usr/share/keyrings/example-repo.gpg] https://example.com/repo stable main

On Ubuntu 24.04 using the newer deb822 format, the equivalent entry looks like this.

Types: deb
URIs: https://example.com/repo
Suites: stable
Components: main
Signed-By: /usr/share/keyrings/example-repo.gpg

Clean apt's cache and refresh

After editing sources, clear stale package lists so apt rebuilds its cache from the corrected entries.

sudo rm -rf /var/lib/apt/lists/*
sudo apt clean
sudo apt update