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/E101.md.
mfeflow

    MFEFLOW_E101

    A shared singleton is missing from the shared list.

    Fix

    Run mfeflow doctor --fix, or add the package to the singletons list.