Comfy-Org/ComfyUI · error · ValueError

Looping is not available when an end_frame is set.

Error message

Looping is not available when an end_frame is set.

What it means

Raised by LumaRay32ImageToVideoNode (comfy_api_nodes/nodes_luma.py:1109) when loop=True while an end_frame is connected. A loop must end where it started, which conflicts with anchoring the ending to a different image, so the combination is rejected before upload.

Source

Thrown at comfy_api_nodes/nodes_luma.py:1109

            is_api_node=True,
            price_badge=_BADGE_RAY32_VIDEO_5S,
        )

    @classmethod
    async def execute(
        cls,
        prompt: str,
        resolution: str,
        loop: bool,
        seed: int,
        start_frame: torch.Tensor | None = None,
        end_frame: torch.Tensor | None = None,
    ) -> IO.NodeOutput:
        validate_string(prompt, strip_whitespace=True, min_length=1, max_length=6000)
        if start_frame is None and end_frame is None:
            raise ValueError("Provide at least one of start_frame / end_frame.")
        if loop and end_frame is not None:
            raise ValueError("Looping is not available when an end_frame is set.")
        video = Luma2VideoOptions(resolution=resolution, duration="5s", loop=loop or None)
        if start_frame is not None:
            url = await upload_image_to_comfyapi(cls, start_frame, mime_type="image/png")
            video.start_frame = Luma2ImageRef(url=url)
        if end_frame is not None:
            url = await upload_image_to_comfyapi(cls, end_frame, mime_type="image/png")
            video.end_frame = Luma2ImageRef(url=url)
        request = Luma2GenerationRequest(prompt=prompt, model="ray-3.2", type="video", video=video)
        return await _ray32_generate(cls, request)


class LumaRay32KeyframeNode(IO.ComfyNode):
    @classmethod
    def define_schema(cls) -> IO.Schema:
        return IO.Schema(
            node_id="LumaRay32KeyframeNode",
            display_name="Luma Ray 3.2 Keyframe",
            category="partner/video/Luma",

View on GitHub (pinned to 1c6d8d45b3)

Solutions

1. Disconnect end_frame if you want a looping video (loop closes back to start_frame).
2. Or disable loop to keep the explicit end_frame.
3. Use start_frame only plus prompt to control the trajectory of a loop.

if loop and end_frame is not None:
    loop = False  # or drop end_frame

When it happens

Trigger: Executing the Ray 3.2 image-to-video node with loop enabled and both start_frame and end_frame connected (end_frame alone with loop also triggers it).

Common situations: User enables loop for ping-pong output but keeps a distinct end frame wired; settings copied from a non-looping keyframe workflow.

Related errors

• Looping is only available with 5s duration on Ray 3.2.
• Provide at least one of start_frame / end_frame.
• Connect at least 2 Luma Ray 3.2 Keyframe nodes (use Luma Ray
• Ray 3.2 supports at most 64 keyframes; got {len(items)}.
• Keyframe position {item.value:g}s is past the end of the {du

AI-assisted analysis of Comfy-Org/ComfyUI@1c6d8d45b3 (2026-08-14). Data as JSON: /api/errors/09ed9dd98ec4a954. Report an issue: GitHub.