Unity-Technologies/UnityCsReference · error · ArgumentNullException

name

Error message

name

What it means

AssetImporter.SourceAssetIdentifier(Type type, string name) constructor throws ArgumentNullException with param name 'name' when name is null. This is a distinct check from the empty-string check (error 36): null triggers ArgumentNullException, empty string triggers ArgumentException. The name field stores the sub-asset's name for import remapping.

Source

Thrown at Editor/Mono/AssetPipeline/AssetImporter.bindings.cs:47

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

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

            public SourceAssetIdentifier(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;
                this.name = name;
            }

            public Type type;
            public string name;
        }

        [NativeName("AssetPathName")]
        public extern  string assetPath
        {

View on GitHub (pinned to 225b0fbdb5)

Solutions

1. Null-check name: if (name != null) new SourceAssetIdentifier(type, name).
2. Coalesce null to empty string only if empty is acceptable: name = name ?? string.Empty (but note error 36 will fire if empty).
3. Validate serialized data has non-null, non-empty name fields before constructing identifiers.

Example fix

// before
var id = new SourceAssetIdentifier(type, subAssetName);

// after
if (!string.IsNullOrEmpty(subAssetName))
    var id = new SourceAssetIdentifier(type, subAssetName);
else
    Debug.LogWarning($"Skipping SourceAssetIdentifier: name is null or empty for type {type}");

if (!string.IsNullOrEmpty(name))
    var id = new AssetImporter.SourceAssetIdentifier(type, name);
else
    Debug.LogWarning($"Skipping SourceAssetIdentifier: name is null or empty");

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

try { var id = new AssetImporter.SourceAssetIdentifier(type, name); }
catch (ArgumentNullException ex) when (ex.ParamName == "name")
{ Debug.LogWarning($"Skipped SourceAssetIdentifier: name was null"); }

When it happens

Trigger: Constructing new SourceAssetIdentifier(type, null) where the name argument is null. This happens when reading a name from serialized data where the name field is absent/null, or from an asset whose .name property was never set and returned null via a custom path.

Common situations: Remap configuration loaded from external files (JSON/XML) where the name field is optional or omitted. Also occurs when iterating sub-assets whose names are null in edge cases (e.g., unnamed scriptable objects or assets created programmatically without a name).

Related errors

• asset
• type
• The name is empty
• Cannot add dependency on invalid path.
• Cannot add source dependency on empty GUID.

AI-assisted analysis of Unity-Technologies/UnityCsReference@225b0fbdb5 (2026-08-13). Data as JSON: /api/errors/9a6292f253093056. Report an issue: GitHub.