dify - 💡(How to fix) Fix [Bug] External knowledge base retrieval settings (top_k / score_threshold) are not applied on save and retrieval testing

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Dify version

1.14.0

Cloud or Self Hosted

Self Hosted (Docker)

Steps to reproduce

1. Create a new Knowledge Base with provider = external (bound to any external knowledge API).
2. Open Knowledge Base Settings → Retrieval Settings.
3. Change top_k from the default 4 to 7.
4. Click Save.

• Expected: a PATCH request is sent to /console/api/datasets/<id> and the new values are persisted.

• Actual: no network request is fired; the button click silently does nothing.

1. Open DevTools Console. The following error is thrown: TypeError: Cannot read properties of undefined (reading 'reranking_provider_name') at showMultiModalTip useMemo in use-form-state.ts
2. Regardless of step 4, navigate to Retrieval Testing, enter a query and click Testing. Expected request body:

  {
    "external_retrieval_model": {
      "top_k": 7,
      "score_threshold": 0.35,
      "score_threshold_enabled": false
    }
  }

• Actual request body (hard-coded defaults):

  {
    "external_retrieval_model": {
      "top_k": 4,
      "score_threshold": 0.5,
      "score_threshold_enabled": false
    }
  }

✔️ Expected Behavior

1. On the settings page, saving retrieval settings for an external knowledge base should fire a PATCH request and persist the values the user configured.

2. On the retrieval testing page, the request body should use the persisted top_k / score_threshold / score_threshold_enabled, not hard-coded defaults.

❌ Actual Behavior

1. The Save button click does nothing — no PATCH is sent — because a TypeError crashes the hook that owns the button's onClick.

2. Retrieval testing always sends hard-coded defaults (top_k: 4, score_threshold: 0.5, score_threshold_enabled: false), ignoring the user's saved configuration.