CoplayDev/unity-mcp · error · InvalidOperationException

Install Dir resolved to an empty path.

Error message

Install Dir resolved to an empty path.

What it means

After ExpandPath returns, if the result is null/empty/whitespace the sync cannot proceed. This guards the rare case where expansion (e.g. '~' resolved via Environment.GetFolderPath) yields an empty string.

Source

Thrown at MCPForUnity/Editor/Setup/SkillSyncService.cs:688

            var trimmed = installDir.Trim();
            if (trimmed.IndexOfAny(Path.GetInvalidPathChars()) >= 0)
            {
                throw new InvalidOperationException($"Install Dir contains invalid path characters: {installDir}");
            }

            string expandedPath;
            try
            {
                expandedPath = ExpandPath(trimmed);
            }
            catch (Exception ex)
            {
                throw new InvalidOperationException($"Install Dir is invalid and cannot be resolved: {installDir}", ex);
            }

            if (string.IsNullOrWhiteSpace(expandedPath))
            {
                throw new InvalidOperationException("Install Dir resolved to an empty path.");
            }

            return expandedPath;
        }

        internal static string ExpandPath(string path)
        {
            if (string.IsNullOrWhiteSpace(path))
            {
                return string.Empty;
            }

            var expanded = path.Trim();
            if (expanded.StartsWith("~", StringComparison.Ordinal))
            {
                var userHome = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile);
                expanded = Path.Combine(userHome, expanded.Substring(1).TrimStart('/', '\\'));
            }

View on GitHub (pinned to c21bf496bc)

Solutions

1. Provide an absolute path instead of relying on '~' expansion.
2. Ensure the process has a valid user profile/home directory.
3. Set an explicit install directory in Advanced Settings.

var expanded = SkillSyncService.ExpandPath(installDir);
if (string.IsNullOrWhiteSpace(expanded))
{
    throw new ArgumentException("Install dir resolved to empty. Provide an absolute path.");
}

When it happens

Trigger: A tilde path on a headless/container environment where Environment.GetFolderPath(UserProfile) returns empty; an edge case in Path.GetFullPath producing whitespace.

Common situations: Running inside a minimal container or service account with no user profile; CI agent without a home directory.

Related errors

• Install Dir is empty.
• Install Dir contains invalid path characters: {installDir}
• Install Dir is invalid and cannot be resolved: {installDir}
• Failed to write config file '{path}': {ex.Message}
• Source path cannot be empty.

AI-assisted analysis of CoplayDev/unity-mcp@c21bf496bc (2026-08-13). Data as JSON: /api/errors/430f0725d3e7fb48. Report an issue: GitHub.