For AI agents: the complete documentation index is available at https://mfeflow.github.io/mfeflow/llms.txt, the full documentation bundle is available at https://mfeflow.github.io/mfeflow/llms-full.txt, and this page is available as Markdown at https://mfeflow.github.io/mfeflow/errors/E506.md.
mfeflow

    MFEFLOW_E506

    The registry host is not set up or cannot be used.

    Fix

    Pass --host file:

    or s3://[/prefix], or set registry.host in mfeflow.json. Deploys also need --base-url or registry.baseUrl. S3 settings come from MFEFLOW_S3_ENDPOINT, MFEFLOW_S3_REGION, AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY. See https://mfeflow.github.io/mfeflow/guide/deploy-and-rollback.