Unknown Error with LoopAgent example

[salvatorecordiano]

Describe the bug I'm using the python example code on the documentation here https://google.github.io/adk-docs/agents/workflow-agents/loop-agents/#full-example-iterative-document-improvement.

To Reproduce Please share a minimal code and data to reproduce your problem. Steps to reproduce the behavior:

1. Run the example code
2. Start the convesation with adk-web
3. Receive the error "Unknown error."

Expected behavior No error should be displayed.

Screenshots If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: Linux
• Python version: 3.13.3
• ADK version: 1.17.0

Model Information:

• Are you using LiteLLM: No
• Which model is being used: gemini-2.5-flash