Human Approval Node Fails with 400 CLIENT_ERROR in Approval Process Channel (26D)

Summary:

The Human Approval node in Oracle AI Agent Studio fails with a 400 CLIENT_ERROR when using the Approval Process channel in Release 26D.

The Chat channel works correctly, but the Approval Process channel consistently fails, even in a minimal workflow.

Content (please ensure you mask any confidential information):

Hello,

I am testing the Human Approval node in Oracle AI Agent Studio (Release 26D), but I consistently encounter an error when using the Approval Process channel.

I would appreciate any guidance on the possible cause or required configuration.

1. Workflow Configuration

I created a minimal workflow to isolate the issue.

• Workflow: START → Human Approval