Unity-Technologies/UnityCsReference · critical · DirectoryNotFoundException

Bundled dotnet SDK not found at {sdkRoot}

Error message

Bundled dotnet SDK not found at {sdkRoot}

What it means

Thrown by GetDotnetRuntimeVersion (UnityEditorMSBuildPropsTargetsGeneration.cs:269, DirectoryNotFoundException) when the bundled .NET SDK directory at <applicationScriptingPath>/DotNetSdk/sdk does not exist. Unity reads the SDK version from each SDK folder's '.version' file to write sdk.version into the generated global.json; if the SDK root is absent the version cannot be discovered.

Source

Thrown at Editor/Mono/Scripting/ScriptCompilation/MsBuild/UnityEditorMSBuildPropsTargetsGeneration.cs:269

        throw new FileNotFoundException($"No {prefix}*{suffix} package found in {sdkNugetsPath}");
    }

    private static string s_cachedDotnetRuntimeVersion;

    // The .NET SDK version written to the generated global.json (sdk.version) must match the .NET SDK
    // Unity ships. Read it from the SDK's authoritative ".version" metadata (the version is on the
    // second line) rather than trusting the folder name, so a .NET upgrade (8 -> 10 -> ...) needs no
    // change here. We return the full version (e.g. "10.0.102"), preserving minor/patch, and pick the
    // highest if more than one SDK is present.
    private static string GetDotnetRuntimeVersion()
    {
        if (s_cachedDotnetRuntimeVersion != null)
            return s_cachedDotnetRuntimeVersion;

        var sdkRoot = Path.Combine(EditorApplication.applicationScriptingPath, "DotNetSdk", "sdk");
        if (!Directory.Exists(sdkRoot))
            throw new DirectoryNotFoundException($"Bundled dotnet SDK not found at {sdkRoot}");

        string bestVersion = null;
        Version bestParsed = null;
        foreach (var dir in Directory.EnumerateDirectories(sdkRoot))
        {
            // Each SDK folder ships a ".version" file whose second line is the SDK version, e.g.
            //   <commit hash>
            //   8.0.318
            //   <rid>
            var versionFile = Path.Combine(dir, ".version");
            if (!File.Exists(versionFile))
                continue;
            var lines = File.ReadAllLines(versionFile);
            if (lines.Length < 2)
                continue;
            var version = lines[1].Trim();
            if (version.Length == 0)
                continue;

View on GitHub (pinned to 225b0fbdb5)

Solutions

1. Reinstall/repair the Unity Editor to restore the bundled DotNetSdk/sdk directory.
2. Confirm EditorApplication.applicationScriptingPath resolves to the correct install and that the DotNetSdk tree is intact.

var sdkRoot = Path.Combine(EditorApplication.applicationScriptingPath, "DotNetSdk", "sdk");
if (!Directory.Exists(sdkRoot))
    throw new DirectoryNotFoundException(
        $"Bundled .NET SDK missing at {sdkRoot}; reinstall/repair the Unity Editor.");

When it happens

Trigger: Generating the MSBuild global.json for script compilation when the bundled DotNetSdk/sdk folder is missing from the editor install.

Common situations: Corrupt/partial editor install, the bundled .NET SDK removed by a cleanup tool, or an altered application contents path.

Related errors

• Unity SDK nuget feed not found at {sdkNugetsPath}
• No {prefix}*{suffix} package found in {sdkNugetsPath}
• No SDK with a valid .version file found under {sdkRoot}
• Unsupported architecture {RuntimeInformation.ProcessArchitec
• Unsupported architecture {RuntimeInformation.ProcessArchitec

AI-assisted analysis of Unity-Technologies/UnityCsReference@225b0fbdb5 (2026-08-13). Data as JSON: /api/errors/fa1e5d4d982220c0. Report an issue: GitHub.