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/
这是个提示，并不影响部署。
我也遇到你一样的问题，是docker-compose版本太低了，您去卸载这个版本，然后下载最新的版本安装一下，然后重新安装maxkb即可。参看https://blog.51cto.com/u_16213397/12647795