Expecting property name enclosed in double quotes

[shy20221121]

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Dify version

1.10.1

Cloud or Self Hosted

Self Hosted (Docker)

Steps to reproduce

The knowledge base pipeline page is showing an error: Expecting property name enclosed in double quotes: line 5156 column 5 (char 576206).

This error doesn't seem to be reported in the English interface.

✔️ Expected Behavior

A knowledge base pipeline can be created.

❌ Actual Behavior

No response

[dosubot]

This error is caused by malformed JSON being sent from the frontend to the backend—specifically, property names not enclosed in double quotes, which strict JSON parsers require. In Dify, this often happens when localized (non-English) strings in node titles or descriptions introduce problematic characters or formatting that break JSON serialization. The frontend uses JSON.stringify to serialize data, but does not sanitize or escape localized strings, so certain translations can result in invalid JSON. The backend strictly parses incoming JSON and will reject any payload that doesn't comply, leading to the error you see.

As a temporary workaround, switch your interface to English, which avoids the problematic localized strings. For debugging, enable DEBUG=true and FLASK_DEBUG=true in your environment and check the dify-api logs for JSONDecodeError to pinpoint the malformed payload.

To prevent this, localized strings should be sanitized or validated before serialization in the frontend. If you maintain the deployment, consider adding a check to ensure all property names and string values are properly escaped and double-quoted before sending to the backend. For maintainers, adding defensive validation for localized content in both frontend and backend would help prevent similar issues in the future.

More details and recommendations can be found in related discussions and code references:

• Frontend serialization and localization
• Backend strict JSON parsing
• Debugging JSON errors in logs

To reply, just mention @dosu.

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