OpenBMB/ChatDev · error · WorkflowExecutionError

Failed to start workflow: {exc}

Error message

Failed to start workflow: {exc}

What it means

A non-ValidationError exception escaped while starting the workflow (e.g. inside asyncio.create_task setup or workflow_run_service.start_workflow). It is logged via the server logger and re-raised as WorkflowExecutionError with the original exception text.

Source

Thrown at server/routes/execute.py:53

        logger.info(
            "Workflow execution started",
            log_type=LogType.WORKFLOW,
            session_id=request.session_id,
            yaml_file=request.yaml_file,
            task_prompt_length=len(request.task_prompt or ""),
        )

        return {
            "status": "started",
            "session_id": request.session_id,
            "message": "Workflow execution started",
        }
    except ValidationError as exc:
        raise HTTPException(status_code=400, detail=str(exc))
    except Exception as exc:
        logger = get_server_logger()
        logger.log_exception(exc, "Failed to start workflow execution")
        raise WorkflowExecutionError(f"Failed to start workflow: {exc}")

View on GitHub (pinned to 4fb2db0ea9)

Solutions

1. Check the server log entry 'Failed to start workflow execution' for the original traceback and fix that root cause
2. Verify the YAML file path and workflow definition are valid
3. Ensure the session is connected and services initialized before starting
4. If it's an environment issue, restart the server after fixing configuration

# pre-flight: confirm yaml_file and session connection
assert manager_ready(session_id) and yaml_exists(request.yaml_file)

try:
    client.execute_workflow(req)
except WorkflowExecutionError as e:
    log_server_traceback()  # match via server log 'Failed to start workflow execution'
    if 'No such file' in str(e): fix_yaml_path(req)

When it happens

Trigger: POST execute where start_workflow throws an unexpected error: missing config file, IO errors reading the YAML, or internal state problems in the workflow run service.

Common situations: Workflow YAML referencing missing files or tools; race conditions creating the background task; service dependencies (queues, stores) not initialized.

Related errors

• Failed to run workflow: {exc}
• YAML root must be a mapping
• Failed to download session
• YAML root must be a mapping
• Design validation failed for '{config_path}': {formatted}

AI-assisted analysis of OpenBMB/ChatDev@4fb2db0ea9 (2026-08-27). Data as JSON: /api/errors/cf0284f0bd23e62c. Report an issue: GitHub.