microsoft/semantic-kernel · error · DirectoryNotFoundException

The directory '{directoryPath}' does not exist.

Error message

The directory '{directoryPath}' does not exist.

What it means

A DirectoryNotFoundException thrown when the absolute path provided to GenerateMermaidImageAsync points into a directory that does not exist on disk. The renderer refuses to write into a missing directory rather than silently creating it for absolute paths.

Source

Thrown at dotnet/samples/GettingStartedWithProcesses/Utilities/MermaidRenderer.cs:41

        if (!filenameOrPath.EndsWith(".png", StringComparison.OrdinalIgnoreCase))
        {
            throw new ArgumentException("The filename must have a .png extension.", nameof(filenameOrPath));
        }

        string outputFilePath;

        // Check if the user provided an absolute path
        if (Path.IsPathRooted(filenameOrPath))
        {
            // Use the provided absolute path
            outputFilePath = filenameOrPath;

            // Ensure the directory exists
            string directoryPath = Path.GetDirectoryName(outputFilePath)
                ?? throw new InvalidOperationException("Could not determine the directory path.");
            if (!Directory.Exists(directoryPath))
            {
                throw new DirectoryNotFoundException($"The directory '{directoryPath}' does not exist.");
            }
        }
        else
        {
            // Use the assembly's directory for relative paths
            string? assemblyPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
            if (assemblyPath == null)
            {
                throw new InvalidOperationException("Could not determine the assembly path.");
            }

            string outputPath = Path.Combine(assemblyPath, "output");
            Directory.CreateDirectory(outputPath); // Ensure output directory exists
            outputFilePath = Path.Combine(outputPath, filenameOrPath);
        }

        // Download Chromium if it hasn't been installed yet
        BrowserFetcher browserFetcher = new();

View on GitHub (pinned to c028a0c7dc)

Solutions

1. Create the target directory before calling: Directory.CreateDirectory(Path.GetDirectoryName(path)).
2. Use a relative filename so the renderer's assembly 'output' folder branch (which auto-creates) is used.
3. Point to a known-existing directory such as Path.GetTempPath().

Example fix

// before
await MermaidRenderer.GenerateMermaidImageAsync(code, @"C:\out\diagram.png"); // C:\out missing
// after
string dir = @"C:\out"; Directory.CreateDirectory(dir);
await MermaidRenderer.GenerateMermaidImageAsync(code, Path.Combine(dir, "diagram.png"));

string dir = Path.GetDirectoryName(Path.GetFullPath(filename))!;
Directory.CreateDirectory(dir);
await MermaidRenderer.GenerateMermaidImageAsync(code, filename);

bool DirectoryExistsFor(string p) { var d = Path.GetDirectoryName(Path.GetFullPath(p)); return d is not null && Directory.Exists(d); }

try { await MermaidRenderer.GenerateMermaidImageAsync(code, filename); }
catch (DirectoryNotFoundException) { Directory.CreateDirectory(Path.GetDirectoryName(Path.GetFullPath(filename))!); /* retry */ }

When it happens

Trigger: Calling GenerateMermaidImageAsync with an absolute path whose parent directory has not been created (e.g. '/output/x.png' where /output is absent).

Common situations: Hard-coded output folder that was never created; running in an environment where the expected output directory differs; CI sandbox lacking the path.

Related errors

• The filename must have a .png extension.
• Could not determine the directory path.
• Could not determine the assembly path.
• An error occurred while accessing the file.
• Directory for path '{fullFilepath}' does not exist, could no

AI-assisted analysis of microsoft/semantic-kernel@c028a0c7dc (2026-08-13). Data as JSON: /api/errors/ccf32ab743718d4f. Report an issue: GitHub.