dify - 💡(How to fix) Fix Direct Chatflow / Workflow execution hangs with only `event: ping` after migration to 1.13.3, while Agent works normally [2 comments, 2 participants]

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Dify version

1.13.3

Cloud or Self Hosted

Self Hosted (Docker)

Steps to reproduce

Environment

• Dify version: 1.13.3
• Previous Dify version: 1.10
• Deployment type: Self-hosted
• Network environment: Offline / internal network, no public internet access
• Model service: Running normally
• GPU status: GPU resources are not fully occupied
• Affected app types:
  • Chatflow
  • Workflow
• Unaffected app type:
  • Agent

Background

Originally, we were using Dify 1.10.

Later, we installed Dify 1.13.3 and migrated the data from Dify 1.10 to Dify 1.13.3.

Right after the migration was completed, the existing Workflows and Chatflows worked normally. The configured Workflow / Chatflow applications could chat and return responses without any issue.

However, after the service had been running for a period of time, direct Chatflow / Workflow execution started to hang intermittently.

The confusing part is that Agent applications still work normally at the same time.

✔️ Expected Behavior

When running a Chatflow or Workflow directly from the Dify console preview page or through the public API, the request should execute normally and return the workflow/chatflow result.

Expected behavior includes:

• The Chatflow preview window should stop showing the loading state after execution finishes.
• The streaming response should return normal workflow/chatflow events and final output.
• Direct Workflow API calls should return a successful result or a clear error message.
• Direct Chatflow execution should behave consistently with Agent execution.
• If a workflow node, model provider, tool, knowledge base, plugin, or any other component fails, Dify should return an explicit error instead of keeping the request hanging indefinitely.
• Logs from api, worker, and dify-plugin-daemon should contain enough information to identify the failed step if execution cannot continue.

❌ Actual Behavior

Direct Chatflow / Workflow execution intermittently gets stuck.

When the issue occurs:

• In the Dify console preview page, the Chatflow remains in a loading state and never returns the final answer.
• Direct API calls to Workflow / Chatflow hang indefinitely.
• The streaming response only returns:

event: ping

• No final response is returned.
• No visible error message is shown in the UI.
• No error is returned by the API.
• The issue does not necessarily happen immediately after startup. It appears after the Dify service has been running for some time.

At the same time, Agent applications work normally:

• Agent chat responds successfully.
• Agent can call tools normally.
• Agent can use knowledge bases normally.
• Agent can invoke related workflows/chatflows and return results successfully.

This makes the issue appear to be limited to direct Chatflow / Workflow execution paths.