ERROR: Version in "./docker-compose.yml" is unsupported.

[ebadfd]

im getting the below error while doing docker-compose up -d postgresdb

ERROR: Version in "./docker-compose.yml" is unsupported. You might be seeing this error because you're using the wrong Compose file version. Either specify a supported version (e.g "2.2" or "3.3") and place your service definitions under the services key, or omit the version key and place your service definitions at the root of the file to use version 1.
For more on the Compose file format versions, see https://docs.docker.com/compose/compose-file/

[Warlord711]

I had same error, Docker Compose 1.25.
Just replace the docker-compose binary with the latest one from https://github.com/docker/compose/releases

[petport]

For some reason, at the first line of docker-compose.yml has version: "3.9". Just change it to either 2.2 or 3.3

[agathakazar]

Changing to 3.7 worked for me

Debian 11.1
docker-compose version 1.25.0, build unknown
Docker version 20.10.5+dfsg1, build 55c4c88