CoplayDev/unity-mcp · error · InvalidOperationException

Install Dir contains unmanaged files. Please choose an empty

Error message

Install Dir contains unmanaged files. Please choose an empty folder or an existing unity-mcp-skill folder.

What it means

EnsureManagedInstallRoot refuses to manage a directory that already contains files but lacks the .unity-mcp-skill-sync ownership marker and does not match the legacy skill-folder shape (must contain SKILL.md and only top-level dirs that exist remotely). This prevents the sync from deleting unrelated user files.

Source

Thrown at MCPForUnity/Editor/Setup/SkillSyncService.cs:542

            return map;
        }

        private static void EnsureManagedInstallRoot(
            string installPath,
            ICollection<string> localRelativePaths,
            ICollection<string> remoteRelativePaths,
            StringComparer pathComparer)
        {
            var markerPath = Path.Combine(installPath, SyncOwnershipMarker);
            if (File.Exists(markerPath))
            {
                return;
            }

            if (localRelativePaths.Count > 0 && !CanAdoptLegacyManagedRoot(localRelativePaths, remoteRelativePaths, pathComparer))
            {
                throw new InvalidOperationException(
                    "Install Dir contains unmanaged files. " +
                    "Please choose an empty folder or an existing unity-mcp-skill folder.");
            }

            File.WriteAllText(markerPath, "managed-by-unity-mcp-skill-sync");
        }

        private static bool CanAdoptLegacyManagedRoot(
            ICollection<string> localRelativePaths,
            ICollection<string> remoteRelativePaths,
            StringComparer pathComparer)
        {
            if (localRelativePaths.Count == 0)
            {
                return true;
            }

            var remoteTopLevels = new HashSet<string>(pathComparer);

View on GitHub (pinned to c21bf496bc)

Solutions

1. Choose an empty folder as the install directory.
2. Or choose an existing unity-mcp-skill folder that contains the .unity-mcp-skill-sync marker.
3. Move unrelated files out of the target folder before syncing.
4. If adopting a legacy skill folder, ensure it has SKILL.md and matching top-level dirs.

var marker = Path.Combine(installDir, ".unity-mcp-skill-sync");
if (Directory.Exists(installDir) && Directory.EnumerateFileSystemEntries(installDir).Any() && !File.Exists(marker))
{
    throw new InvalidOperationException("Install dir has unmanaged content. Pick an empty folder or an existing unity-mcp-skill folder.");
}

When it happens

Trigger: Install dir pointed at a non-empty folder with foreign content (project root, Desktop, a sibling package); a previous sync's marker was deleted; the folder has files whose top-level segments do not match the remote layout.

Common situations: User picked the wrong folder in the directory dialog; reused a folder that held other content; marker file was manually removed or gitignored away.

Related errors

• Failed to write config file '{path}': {ex.Message}
• The selected uvx executable does not exist
• The selected Claude CLI executable does not exist
• Install Dir is invalid and cannot be resolved: {installDir}
• Could not generate a unique screenshot filename for '{fullPa

AI-assisted analysis of CoplayDev/unity-mcp@c21bf496bc (2026-08-13). Data as JSON: /api/errors/a84540a7cdb54414. Report an issue: GitHub.