{"record":{"id":"16a536859e8c8b33","repo":"stride3d/stride","slug":"the-associated-asset-type-does-not-have-a-public","errorCode":null,"errorMessage":"The associated asset type does not have a public parameterless constructor.","messagePattern":"The associated asset type does not have a public parameterless constructor\\.","errorType":"exception","errorClass":"InvalidOperationException","httpStatus":null,"severity":"error","filePath":"sources/assets/Stride.Core.Assets/DefaultAssetFactory.cs","lineNumber":22,"sourceCode":"namespace Stride.Core.Assets;\n\n/// <summary>\n/// An implementation of the <see cref=\"AssetFactory{T}\"/> class that uses the default public parameterless constructor\n/// of the associated asset type.\n/// </summary>\n/// <typeparam name=\"T\">The type of asset this factory can create.</typeparam>\npublic class DefaultAssetFactory<T> : AssetFactory<T> where T : Asset\n{\n    public static T Create()\n    {\n        return Activator.CreateInstance<T>()!;\n    }\n\n    /// <inheritdoc/>\n    public override T New()\n    {\n        if (typeof(T).GetConstructor(Type.EmptyTypes) == null)\n            throw new InvalidOperationException(\"The associated asset type does not have a public parameterless constructor.\");\n\n        return Create();\n    }\n}\n","sourceCodeStart":4,"sourceCodeEnd":27,"githubUrl":"https://github.com/stride3d/stride/blob/96fad776d210c221682aac1ccdf4c79dc046fc38/sources/assets/Stride.Core.Assets/DefaultAssetFactory.cs#L4-L27","documentation":"Stride's DefaultAssetFactory<T>.New() creates a new instance of the associated asset type T. Before instantiating, it verifies that T exposes a public parameterless constructor via reflection; if not, it throws this InvalidOperationException because the factory cannot construct the asset.","triggerScenarios":"Calling New() on a factory whose generic type T (an Asset subclass) has no public parameterless constructor — e.g. the type only defines constructors with parameters or its parameterless constructor is private/internal.","commonSituations":"Registering a custom asset type in the asset factory system where the author added a convenience constructor with required parameters and removed the implicit default constructor; abstract types; compiler-generated types.","solutions":["Add a public parameterless constructor to the asset type used as T","Ensure the type is concrete (not abstract) and the ctor is public","Use a factory/type that supports constructor arguments instead of DefaultAssetFactory"],"exampleFix":"// before\npublic class MyAsset : Asset\n{\n    public MyAsset(string name) { Name = name; }\n}\n// after\npublic class MyAsset : Asset\n{\n    public MyAsset() { }\n    public MyAsset(string name) { Name = name; }\n}","handlingStrategy":"validation","validationCode":"if (typeof(T).GetConstructor(Type.EmptyTypes) == null) throw new InvalidOperationException($\"{typeof(T)} needs a public parameterless ctor\");","typeGuard":"static bool HasDefaultCtor<T>() => typeof(T).GetConstructor(Type.EmptyTypes) != null;","tryCatchPattern":"try { asset = factory.New(); } catch (InvalidOperationException ex) { log.Error(ex.Message); }","preventionTips":["Always define a public parameterless constructor on Asset subclasses","Keep asset types concrete and simple (data holders)","Add a unit test that instantiates every registered asset type via New()"],"tags":["reflection","assets","constructor"],"backgroundTag":"missing-parameterless-constructor","analyzedSha":"96fad776d210c221682aac1ccdf4c79dc046fc38","analyzedAt":"2026-09-14T02:59:31.279Z","contentChangedAt":"2026-09-14T02:59:31.279Z","schemaVersion":2},"datasetVersion":"2026-09-15T23:17:13.987Z"}