> 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.

# MFEFLOW_E306

A dev server could not start.

## Fix

Free the port or change it in mfeflow\.json and the app's rsbuild config, then run `mfeflow dev` again.