I found a similar open issue related to a 500 error in the Dify webapp-conversation module. The suggested solution involves checking several configurations and environment variables in your Docker setup:

1. API URLs: Ensure that all API URLs are correctly set and accessible.
2. Enable Debugging: Set DEBUG=true and FLASK_DEBUG=true to get more detailed error messages.
3. Database Configuration: Verify that your PostgreSQL database configuration is correct.
4. Redis Configuration: Ensure your Redis configuration is correct.
5. Celery Configuration: Check your Celery broker URL.
6. CORS Configuration: Ensure CORS settings are correctly configured.
7. Storage Configuration: Verify that the storage path is correctly set and accessible.
8. Sentry Configuration: If using Sentry, ensure the DSN is correctly set.

After verifying and updating these configurations, restart your Docker containers to apply the changes. This should help resolve the "Internal Server Error" you are encountering ^[1].

To continue talking to Dosu, mention @dosu.

^{Help Dosu learn! Give it feedback: Great Response | Irrelevant Answer | Incorrect Sources | Too Verbose | Hallucination | Other}

Please provide the logs of the web page.

It seems you are running the project with source code? But you labeled with docker, so I am a little bit confused here. Can you clarify this?
The error code 502 suggest the backend does not start correctly, please check the backend logs.