Ahead of this change, if you are using the following Remote Docker versions, the recommendation is to use the default version as it is now being kept up-to-date.
docker-17.03.0-ce
docker-17.05.0-ce
docker-17.06.0-ce
docker-17.07.0-ce
docker-17.09.0-ce
docker-17.11.0-ce
docker-17.12.1-ce
docker-18.03.0-ce
docker-18.03.1-ce
docker-18.05.0-ce
docker-18.06.0-ce
docker-18.09.3
docker-19.03.8
docker-19.03.12
docker-19.03.13
docker-19.03.14
docker-20.10.2
docker-20.10.6
docker-20.10.7
docker-20.10.11
docker-20.10.12
This is to avoid a possible a risk of incompatibility with the more current software in the new architecture and the older version of Docker being specified in job’s config file. An email will be sent out to the 10 users who ran the most jobs on CircleCI in the past 30 days and a billing contact for your VCS organization for organizations that have at least one job that is using an older version of Docker.
You can use the default version by eliminating the specific version command in your config.yml.