Failed To Fetch Https //download.docker.com/linux/ubuntu/dists/xenial/inrelease [extra Quality] < EXCLUSIVE · ANTHOLOGY >

: Ensure the line looks exactly like this, manually replacing any non-Ubuntu codenames with xenial :

The error typically occurs when your Ubuntu 16.04 (Xenial Xerus) system cannot communicate with the official Docker repository. This can happen due to an outdated GPG key, a misconfigured repository file, or because you are using a derivative distribution like Linux Mint that is incorrectly identifying itself to Docker's servers. 1. Update Your Docker GPG Key

: Run sudo apt-get install --reinstall ca-certificates . : Ensure the line looks exactly like this,

If you are using a derivative like Linux Mint 18 (which is based on Ubuntu 16.04 Xenial), your system might try to use its own codename (e.g., serena ) in the URL, which Docker does not recognize.

: Ensure your system clock is accurate. If it is off by more than a few minutes, the SSL handshake with download.docker.com will fail. 4. Remove Conflicting Legacy Files Update Your Docker GPG Key : Run sudo

Change your distribution name to xenial in your .list files. Update ca-certificates and check your system date/time. Old Repositories

deb [arch=amd64 signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu xenial stable Use code with caution. Source: Docker Forums 3. Check System Certificates and Time If it is off by more than a

Run the following command to add the latest official Docker GPG key:

An outdated ca-certificates package or an incorrect system clock can break the secure (HTTPS) connection to the Docker download server.

Sometimes old repository entries from apt.dockerproject.org (the old Docker repo) conflict with the new download.docker.com address. Remove old Docker source files: sudo rm /etc/apt/sources.list.d/docker.list Use code with caution. Clean the apt cache: sudo apt-get clean sudo apt-get update Use code with caution. Source: GitHub Moby Issues Summary Checklist Re-add the Docker GPG key to /etc/apt/keyrings/ . Wrong Codename