Unity-Technologies/UnityCsReference · error · ArgumentNullException

type

Error message

type

What it means

AssetIdentifier pairs a System.Type with a name to identify a source asset inside the SpeedTree importer pipeline. The AssetIdentifier(Type, string) constructor guards its first argument: a null Type is rejected with ArgumentNullException because the identifier stores type.ToString() and a null Type would otherwise surface as a NullReferenceException much later during serialization/remapping. The check keeps the failure local and the message specific.

Source

Thrown at Editor/Mono/AssetPipeline/SpeedTree/SpeedTreeImporterSettings.cs:154

        public string type;
        public string name;

        public AssetIdentifier(UnityEngine.Object asset)
        {
            if (asset == null)
            {
                throw new ArgumentNullException("asset");
            }

            this.type = asset.GetType().ToString();
            this.name = asset.name;
        }

        public AssetIdentifier(Type type, string name)
        {
            if (type == null)
            {
                throw new ArgumentNullException("type");
            }

            if (name == null)
            {
                throw new ArgumentNullException("name");
            }

            if (string.IsNullOrEmpty(name))
            {
                throw new ArgumentException("The name is empty", "name");
            }

            this.type = type.ToString();
            this.name = name;
        }
    }

    /// <summary>

View on GitHub (pinned to 225b0fbdb5)

Solutions

1. Resolve the Type before constructing and validate it is non-null (e.g. var t = Type.GetType(typeName); if (t == null) throw new InvalidOperationException("Unknown type " + typeName);).
2. If the type came from reflection, prefer typeof(KnownType) or a known assembly-qualified name so the lookup cannot silently fail.
3. Catch the failure at the boundary (config load) and report the offending type name rather than letting it reach the constructor.

Example fix

// before
var id = new AssetIdentifier(Type.GetType(cfg.typeName), cfg.name);

// after
var t = Type.GetType(cfg.typeName);
if (t == null)
    throw new InvalidOperationException("Unknown type: " + cfg.typeName);
var id = new AssetIdentifier(t, cfg.name);

Type ResolveType(string typeName) {
    var t = Type.GetType(typeName);
    if (t == null)
        throw new InvalidOperationException("Unknown type: " + typeName);
    return t;
}
// then: new AssetIdentifier(ResolveType(cfg.typeName), cfg.name);

static bool IsValidIdentifierType(Type t) => t != null;

When it happens

Trigger: Calling new AssetIdentifier(null, someName); passing a Type obtained via Type.GetType(typeName) or assembly.GetType(typeName) where the lookup silently returned null; building identifiers from deserialized config whose type field failed to resolve.

Common situations: Type-load-by-name that fails after a rename or after moving a class between assemblies; config/asset references that name a type no longer present after a Unity upgrade; unit tests scaffolding identifiers with a placeholder null.

Related errors

• name
• materialFolderPath
• Invalid material folder path: {0}.
• asset
• The name is empty

AI-assisted analysis of Unity-Technologies/UnityCsReference@225b0fbdb5 (2026-08-13). Data as JSON: /api/errors/a87515cc2b8d4e86. Report an issue: GitHub.