LykosAI/StabilityMatrix · error · FileNotFoundException

Source file does not exist

Error message

Source file does not exist

What it means

ComfyClient.UploadFileAsync uploads a local file to the ComfyUI server's input directory. Before copying it checks sourceFile.Exists and throws FileNotFoundException carrying both a message and the source path. The server-side upload cannot proceed without the local source, so the client fails fast.

Solutions

1. Check File.Exists(sourcePath) before calling UploadFileAsync and fail the prompt upload gracefully
2. Normalize/validate all file paths embedded in workflow prompts before queueing
3. Re-export or re-add the missing input asset
4. Catch FileNotFoundException in UploadPromptFiles and report which file is missing

Example fix

// before
await client.UploadFileAsync(sourcePath, destinationRelativePath);
// after
if (!File.Exists(sourcePath))
{
    Logger.Warn("Skipping upload, missing source: {Path}", sourcePath);
    return;
}
await client.UploadFileAsync(sourcePath, destinationRelativePath);

foreach (var path in promptFilePaths)
    if (!File.Exists(path)) throw new FileNotFoundException("Missing prompt input", path);

static bool Uploadable(string? p) => File.Exists(p) && new FileInfo(p).Length > 0;

try { await client.UploadFileAsync(sourcePath, destRelPath); }
catch (FileNotFoundException ex) { Logger.Warn("Upload aborted, missing: {File}", ex.FileName); }

When it happens

Trigger: Calling UploadFileAsync (via UploadPromptFiles) with a sourcePath that does not exist — e.g. an image path referenced in a workflow prompt that was deleted, or a relative path from a workflow JSON that is invalid on this machine.

Common situations: Queueing a saved workflow that references input images not present on the new machine; paths from imported workflows built on another OS with different path separators.

Understand the failure class

Background: "File not found" and ENOENT errors: why libraries can't find a file that should exist — this error's family across 50 libraries.

Related errors

• Sampler not selected
• : Model not selected
• Scheduler not selected
• BaseClipVision not set
• Source directory not found

AI-assisted analysis of LykosAI/StabilityMatrix@af93d6ef57 (2026-09-12). Data as JSON: /api/errors/902cc917357ef5cd. Report an issue: GitHub.

Appendix: source

Thrown at StabilityMatrix.Core/Inference/ComfyClient.cs:394

        CancellationToken cancellationToken = default
    )
    {
        cancellationToken.ThrowIfCancellationRequested();

        // Currently there is no api, so we do a local file copy
        if (LocalServerPath is null)
        {
            throw new InvalidOperationException("LocalServerPath is not set");
        }

        var sourceFile = new FilePath(sourcePath);
        var destFile = LocalServerPath.JoinFile(destinationRelativePath);

        Logger.Info("Copying file from {Source} to {Dest}", sourcePath, destFile);

        if (!sourceFile.Exists)
        {
            throw new FileNotFoundException("Source file does not exist", sourcePath);
        }

        destFile.Directory?.Create();

        await sourceFile.CopyToAsync(destFile, true).ConfigureAwait(false);
    }

    public async Task<Dictionary<string, List<ComfyImage>?>> GetImagesForExecutedPromptAsync(
        string promptId,
        CancellationToken cancellationToken = default
    )
    {
        // Get history for images
        var history = await comfyApi.GetHistory(promptId, cancellationToken).ConfigureAwait(false);

        // Get the current prompt history
        var current = history[promptId];

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