no such image: compreface-api:: invalid reference format

[Roman-]

I am new with docker but I'm following the Getting started guide from the README of this repo. Downloaded 0.4.1 release, unzipped docker-compose.yml and executed the command:

$docker-compose up -d

WARNING: The postgres_password variable is not set. Defaulting to a blank string.
WARNING: The registry variable is not set. Defaulting to a blank string.
WARNING: The ADMIN_VERSION variable is not set. Defaulting to a blank string.
WARNING: The postgres_domain variable is not set. Defaulting to a blank string.
WARNING: The postgres_port variable is not set. Defaulting to a blank string.
WARNING: The enable_email_server variable is not set. Defaulting to a blank string.
WARNING: The email_host variable is not set. Defaulting to a blank string.
WARNING: The email_username variable is not set. Defaulting to a blank string.
WARNING: The email_from variable is not set. Defaulting to a blank string.
WARNING: The email_password variable is not set. Defaulting to a blank string.
WARNING: The compreface_admin_java_options variable is not set. Defaulting to a blank string.
WARNING: The API_VERSION variable is not set. Defaulting to a blank string.
WARNING: The compreface_api_java_options variable is not set. Defaulting to a blank string.
WARNING: The save_images_to_db variable is not set. Defaulting to a blank string.
WARNING: The FE_VERSION variable is not set. Defaulting to a blank string.
WARNING: The CORE_VERSION variable is not set. Defaulting to a blank string.
Creating network "compreface_default" with the default driver
ERROR: no such image: compreface-api:: invalid reference format

Ubuntu 16.04LTS, docker-compose version 1.23.2.

[Roman-]

Turned out I was missing .env file from the .zip archive 🤦‍♂️