LykosAI/StabilityMatrix · error · ValidationException

No ImageSource

Error message

No ImageSource

What it means

ControlNetModule.OnApplyStep throws this ValidationException while adding a ComfyNodeBuilder.LoadImage node: the ControlNet card's SelectImageCardViewModel.ImageSource is null, so there is no image hash file to pass to the ControlNet load-image node. A ControlNet unit fundamentally needs an input image, so the builder aborts workflow generation.

Solutions

1. Select or import an image in the ControlNet card's image area before generating.
2. Programmatically set card.SelectImageCardViewModel.ImageSource to a valid ImageSource before running.
3. Disable or remove the ControlNet module if it is not needed for this generation.
4. Re-add the missing image file so its hash-backed filename can be resolved in the 'Inference' images directory.

Example fix

// before
controlNetCard.SelectedModel = cnModel; // no image set
await vm.Generate();
// after
controlNetCard.SelectedModel = cnModel;
controlNetCard.SelectImageCardViewModel.ImageSource = await imageFile.SaveToImageInferenceManagement("Inference");
await vm.Generate();

if (controlNetCard.SelectImageCardViewModel.ImageSource is null)
    throw new InvalidOperationException("ControlNet requires an input image");

var hasImage = controlNetCard.SelectImageCardViewModel.ImageSource is not null;

try { await vm.Generate(); }
catch (ValidationException ex) when (ex.Message == "No ImageSource")
{
    // prompt user to add a ControlNet input image
}

When it happens

Trigger: Enabling/including a ControlNet module in the inference pipeline without selecting an image in the ControlNet card's image selector before generation.

Common situations: User adds a ControlNet card, picks a model and preprocessor, but forgets to drop/select the reference image; imported workflow JSON references an image missing from the Inference images directory so ImageSource resolves to null; image was deleted after being selected.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• No ImageSource
• No SelectedModel
• Length cannot be null when latentType is Hunyuan
• Prompt extensions not installed
• Model not selected

AI-assisted analysis of LykosAI/StabilityMatrix@af93d6ef57 (2026-09-12). Data as JSON: /api/errors/f79288e751c37cdc. Report an issue: GitHub.

Appendix: source

Thrown at StabilityMatrix.Avalonia/ViewModels/Inference/Modules/ControlNetModule.cs:52

                is { ImageSource: { } image, IsImageFileNotFound: false }
        )
        {
            yield return image;
        }
    }

    /// <inheritdoc />
    protected override void OnApplyStep(ModuleApplyStepEventArgs e)
    {
        var card = GetCard<ControlNetCardViewModel>();

        var image = e.Nodes.AddTypedNode(
            new ComfyNodeBuilder.LoadImage
            {
                Name = e.Nodes.GetUniqueName("ControlNet_LoadImage"),
                Image =
                    card.SelectImageCardViewModel.ImageSource?.GetHashGuidFileNameCached("Inference")
                    ?? throw new ValidationException("No ImageSource")
            }
        ).Output1;

        if (card.SelectedPreprocessor is { } preprocessor && preprocessor != ComfyAuxPreprocessor.None)
        {
            var aioPreprocessor = e.Nodes.AddTypedNode(
                new ComfyNodeBuilder.AIOPreprocessor
                {
                    Name = e.Nodes.GetUniqueName("ControlNet_Preprocessor"),
                    Image = image,
                    Preprocessor = preprocessor.ToString(),
                    // Use lower of width and height for resolution
                    Resolution = Math.Min(card.Width, card.Height)
                }
            );

            image = aioPreprocessor.Output;
        }

View on GitHub (pinned to af93d6ef57)