stride3d/stride · error · InvalidOperationException

Unable to find a serializer for

Error message

Unable to find a serializer for [{0}]

What it means

Load looks up a serializer by the file extension of the path passed in; FindSerializer returned null because no registered serializer handles that extension. The library only knows how to load assets whose extension matches a registered IAssetSerializer. This is a configuration/registration problem, not data corruption.

Solutions

1. Check the file path passed to Load has the correct asset extension (e.g. '.sdtex', '.sdscene')
2. Register a serializer for the extension via the serializer registration used by FindSerializer
3. Verify the file actually is a Stride asset and not a plain text/binary file
4. Log assetFileExtension right before Load to confirm what extension is being resolved

Example fix

// before
var result = AssetFileSerializer.Load<Texture>(stream, "logo.png");
// after
var result = AssetFileSerializer.Load<Texture>(stream, "logo.sdtex");

var ext = Path.GetExtension(filePath).ToLowerInvariant();
if (AssetFileSerializer.FindSerializer(ext) == null)
    throw new InvalidOperationException($"No serializer registered for '{ext}'");

try { AssetFileSerializer.Load<T>(stream, path, log); }
catch (InvalidOperationException ex) when (ex.Message.StartsWith("Unable to find a serializer"))
{ log.Error($"Unsupported asset extension for {path}: {ex.Message}"); }

When it happens

Trigger: Calling AssetFileSerializer.Load<T> with a stream and a filePath whose extension (lowercased) is not registered, e.g. '.txt', '.json', or a missing/renamed extension on the UFile path.

Common situations: Passing a temp/download file with wrong extension; opening a custom asset format without registering a serializer; typos in extension; trying to load non-asset files through the asset loader.

Understand the failure class

Background: 'Could not be found', 'does not exist', 'not found in database': the resource-not-found family when an ID, slug, key, or URI lookup comes back empty — this error's family across 20 libraries.

Related errors

• Could not find a valid content serializer for
• Unable to find a serializer for
• Could not find serializer for generic dependent type
• Can't find serializer for type
• SetAssetObject has already been called with a different…

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/e85f77c88b38082e. Report an issue: GitHub.

Appendix: source

Thrown at sources/assets/Stride.Core.Assets/AssetFileSerializer.cs:102

    /// </summary>
    /// <typeparam name="T">Type of the asset</typeparam>
    /// <param name="filePath">The file path.</param>
    /// <param name="log">The logger.</param>
    /// <returns>An instance of Asset not a valid asset asset object file.</returns>
    public static AssetLoadResult<T> Load<T>(string filePath, ILogger? log = null, string? assetNamespace = null)
    {
        using var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read);
        var result = Load<T>(stream, filePath, log, assetNamespace);
        return result;
    }

    public static AssetLoadResult<T> Load<T>(Stream stream, UFile filePath, ILogger? log = null, string? assetNamespace = null)
    {
        ArgumentNullException.ThrowIfNull(filePath);
        var assetFileExtension = Path.GetExtension(filePath).ToLowerInvariant();

        var serializer = FindSerializer(assetFileExtension)
            ?? throw new InvalidOperationException("Unable to find a serializer for [{0}]".ToFormat(assetFileExtension));
        var asset = (T)serializer.Load(stream, filePath, log, true, out var aliasOccurred, out var yamlMetadata, assetNamespace);
        return new AssetLoadResult<T>(asset, log, aliasOccurred, yamlMetadata);
    }

    /// <summary>
    /// Serializes an <see cref="Asset" /> to the specified file path.
    /// </summary>
    /// <param name="filePath">The file path.</param>
    /// <param name="asset">The asset object.</param>
    /// <param name="yamlMetadata"></param>
    /// <param name="log">The logger.</param>
    /// <exception cref="System.ArgumentNullException">filePath</exception>
    public static void Save(string filePath, object asset, AttachedYamlAssetMetadata? yamlMetadata, ILogger? log = null, string? assetNamespace = null)
    {
        ArgumentNullException.ThrowIfNull(filePath);

        // Creates automatically the directory when saving an asset.
        filePath = FileUtility.GetAbsolutePath(filePath);

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