# DECISION_LOCKED

- Surface: API
- HTTP status: 409
- Recommended action: `CREATE_NEW_RUN`
- Details: `{ lockedFields: string[], currentRunId: string, attemptedChange: string, recommendedAction: RecommendedAction }`

## Cause

A decision-family or alpha setting was edited on a running Run. These fix the statistical test, and moving them mid-Run invalidates the result.

## Fix

Clone the Experiment into a new draft Run and set the decision family there, then Start it. `details.lockedFields` names the settings that are sealed.

## Related

- [RUN_FROZEN](https://splitch.dev/docs/error/RUN_FROZEN)
- [EXPERIMENT_NO_DRAFT](https://splitch.dev/docs/error/EXPERIMENT_NO_DRAFT)

Source: https://splitch.dev/docs/error/DECISION_LOCKED