mattermost-docker Deployment Fails to Start after Upgrading to Latest

Problem

I'm trying to install Mattermost using Docker via https://github.com/mattermost/mattermost-docker After upgrading to the latest version, I'm no longer able to start the Docker deployment due to database errors.

Solution

The mattermost-docker repository uses an older, outdated version of PostgreSQL which is no longer supported by Mattermost.

The repository https://github.com/mattermost/docker is fully supported and admins are advised to migrate to this repository and/or can use it for new deployments.

The 'mattermost-docker' repository will soon be archived and support requests outside of migration to the new repository will not be answered.