Comfy-Org/ComfyUI · error · Exception

Polling endpoint returned non-JSON response.

Error message

Polling endpoint returned non-JSON response.

What it means

Error "Polling endpoint returned non-JSON response." thrown in Comfy-Org/ComfyUI.

Source

Thrown at comfy_api_nodes/util/client.py:360

                    wait_label="Checking",
                    estimated_duration=None,
                    as_binary=False,
                    final_label_on_success=None,
                    monitor_progress=False,
                )
                if not isinstance(resp_json, dict):
                    raise Exception("Polling endpoint returned non-JSON response.")
            except ProcessingInterrupted:
                if cancel_endpoint:
                    with contextlib.suppress(Exception):

View on GitHub (pinned to 1c6d8d45b3)

Solutions

1. Retry polling; the endpoint returned a non-JSON response.

When it happens

Trigger: Thrown at comfy_api_nodes/util/client.py:360 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of Comfy-Org/ComfyUI@1c6d8d45b3 (2026-08-14). Data as JSON: /api/errors/672345c5d7bb6d30. Report an issue: GitHub.