Unity-Technologies/UnityCsReference · error · ArgumentException

The name is empty

Error message

The name is empty

What it means

The third guard in AssetIdentifier(Type, string): once name is non-null it must also be non-empty, because an empty name is a valid C# string but a meaningless key for the importer's remapping tables (it would match nothing or collide with other empty-named entries). The library treats empty as a usage error distinct from null and throws ArgumentException so callers can tell the two mistakes apart.

Source

Thrown at Editor/Mono/AssetPipeline/SpeedTree/SpeedTreeImporterSettings.cs:164

            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>
    /// This attribute is used as a callback to set SRP specific properties from the importer.
    /// </summary>
    [AttributeUsage(AttributeTargets.Method, AllowMultiple = true)]
    public class MaterialSettingsCallbackAttribute : Attribute
    {
        /// <summary>
        /// The version of the method.
        /// </summary>
        public int MethodVersion;

View on GitHub (pinned to 225b0fbdb5)

Solutions

1. Guarantee the name is a non-empty string before constructing; validate with !string.IsNullOrEmpty(name).
2. If the name comes from a path or filename, sanitize/generate a fallback name (e.g. Path.GetFileNameWithoutExtension) so it can never be empty.
3. Reject the offending asset upstream in the import flow with a clear message rather than constructing an invalid identifier.

Example fix

// before
var id = new AssetIdentifier(type, asset.name);

// after
if (string.IsNullOrEmpty(asset.name))
    throw new InvalidOperationException("Asset name is empty for " + asset);
var id = new AssetIdentifier(type, asset.name);

string RequireNonEmptyName(string name) {
    if (string.IsNullOrEmpty(name))
        throw new InvalidOperationException("Asset name is empty.");
    return name;
}
// then: new AssetIdentifier(type, RequireNonEmptyName(asset.name));

static bool IsValidIdentifierName(string name) => !string.IsNullOrEmpty(name);

When it happens

Trigger: Calling new AssetIdentifier(type, ""); passing asset.name where the asset was created but never assigned a meaningful name; trimming user input down to empty.

Common situations: Imported assets with default empty names; editor tooling that lets users clear a name field; scripts that derive names from filenames and hit an edge case producing empty.

Related errors

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

AI-assisted analysis of Unity-Technologies/UnityCsReference@225b0fbdb5 (2026-08-13). Data as JSON: /api/errors/72570d0a4311c019. Report an issue: GitHub.