LykosAI/StabilityMatrix · error · InvalidOperationException

CLIP-L model not found

Error message

CLIP-L model not found

What it means

The Flux Kontext pipeline needs the CLIP-L text encoder (first of two encoders). SelectModels looks for a local ClipModels file whose name contains 'clip_l' and throws this InvalidOperationException when none is installed, since the workflow cannot be built without it.

Solutions

1. Download clip_l.safetensors into the TextEncoders folder and refresh the index
2. Ensure the filename contains the substring 'clip_l' (underscore) in a scanned folder
3. Catch InvalidOperationException and offer an in-app download of clip_l

Example fix

// before
var models = fluxKontextModelManager.SelectModels();
// after
if (!clientManager.ClipModels.Any(m => m.Local != null && m.FileName.Contains("clip_l", StringComparison.OrdinalIgnoreCase)))
{
    await sharedFolders.DownloadModelAsync(ClipLSafetensorsUri, SharedFolderType.TextEncoders);
}
var models = fluxKontextModelManager.SelectModels();

var clip1 = clientManager.ClipModels.FirstOrDefault(m => m.Local != null
    && m.FileName.Contains("clip_l", StringComparison.OrdinalIgnoreCase));
if (clip1 is null) throw new UserDownloadableError("clip_l.safetensors is not installed.");

bool HasClipL(IEnumerable<HybridModelFile> clips) => clips.Any(m => m.Local != null && m.FileName.Contains("clip_l", StringComparison.OrdinalIgnoreCase));

try
{
    var models = fluxKontextModelManager.SelectModels();
}
catch (InvalidOperationException ex) when (ex.Message.Contains("CLIP-L model not found"))
{
    // trigger clip_l download flow
}

When it happens

Trigger: Calling SelectModels when no ClipModels entry has Local != null and a filename containing 'clip_l' (case-insensitive).

Common situations: User installs the T5-XXL encoder but skips clip_l.safetensors; file renamed (e.g. clip-l.safetensors with a hyphen would still contain 'clip_l'? no — hyphen breaks the match); encoders placed in a non-scanned folder.

Understand the failure class

Background: 'Could not be found', 'does not exist', 'not found in database': the resource-not-found family when an ID, slug, key, or URI lookup comes back empty — this error's family across 20 libraries.

Related errors

• Flux.2 Klein UNET model not found
• Flux.2 VAE model not found
• Klein 9B requires the qwen_3_8b text encoder, which isn't…
• Klein 4B requires the qwen_3_4b text encoder, which isn't…
• Flux Kontext UNET model not found

AI-assisted analysis of LykosAI/StabilityMatrix@af93d6ef57 (2026-09-12). Data as JSON: /api/errors/03ebeafe57f115c7. Report an issue: GitHub.

Appendix: source

Thrown at StabilityMatrix.Avalonia/Services/FluxKontextModelManager.cs:183

    {
        var unetModel =
            clientManager.UnetModels.FirstOrDefault(m =>
                m.Local != null
                && (
                    m.FileName.Contains("flux1-dev-kontext", StringComparison.OrdinalIgnoreCase)
                    || m.FileName.Contains("flux-kontext", StringComparison.OrdinalIgnoreCase)
                )
            ) ?? throw new InvalidOperationException("Flux Kontext UNET model not found");

        var vaeModel =
            clientManager.VaeModels.FirstOrDefault(m =>
                m.Local != null && m.FileName.Equals("ae.safetensors", StringComparison.OrdinalIgnoreCase)
            ) ?? throw new InvalidOperationException("Flux VAE model not found");

        var clip1Model =
            clientManager.ClipModels.FirstOrDefault(m =>
                m.Local != null && m.FileName.Contains("clip_l", StringComparison.OrdinalIgnoreCase)
            ) ?? throw new InvalidOperationException("CLIP-L model not found");

        var clip2Model =
            clientManager.ClipModels.FirstOrDefault(m =>
                m.Local != null
                && (
                    m.FileName.Contains("t5xxl", StringComparison.OrdinalIgnoreCase)
                    || m.FileName.Contains("t5-xxl", StringComparison.OrdinalIgnoreCase)
                )
            ) ?? throw new InvalidOperationException("T5-XXL model not found");

        return new FluxKontextWorkflowBuilder.SelectedModels(unetModel, vaeModel, clip1Model, clip2Model);
    }
}

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