EllanJiang/GameFramework · error · GameFrameworkException

Reference type is not a non-abstract class type.

Error message

Reference type is not a non-abstract class type.

What it means

ReferencePool requires every pooled type to be a concrete (non-abstract) class, because the pool must be able to instantiate it with new(). InternalCheckReferenceType rejects interface or abstract types with this message on all entry points (Acquire, Release, Add, Remove, RemoveAll).

Solutions

1. Use only concrete, instantiable classes implementing IReference for all ReferencePool calls.
2. If you have several implementations, register each concrete type separately (Add<ImplA>(n), Add<ImplB>(n)).
3. Add a static check or unit test that iterates your registered types and asserts !type.IsAbstract.

Example fix

// before
ReferencePool.Add<IReference>(100); // interface type

// after
ReferencePool.Add<MyConcreteReference>(100); // concrete class implementing IReference

System.Diagnostics.Debug.Assert(
    typeof(T).IsClass && !typeof(T).IsAbstract,
    "ReferencePool requires a concrete class, got: " + typeof(T).FullName);

static bool IsConcreteClass(Type t) => t != null && t.IsClass && !t.IsAbstract;

try { ReferencePool.Add<T>(count); }
catch (GameFrameworkException ex) when (ex.Message.Contains("non-abstract class"))
{
    // T is an interface or abstract class — switch to each concrete implementation
}

When it happens

Trigger: Calling ReferencePool.Add<T>, Acquire<T>, or Remove<T> where T is an interface (e.g. IReference itself) or an abstract base class of your reference hierarchy.

Common situations: Trying to pre-warm a pool against an interface 'for all implementers' — pooling is per concrete type, not per interface; registering an abstract base in generic pool-initialization loops over a hierarchy.

Understand the failure class

Background: Type mismatch errors: IllegalArgumentException, TypeError and type guards across 150 open-source libraries — this error's family across 150 libraries.

Related errors

• Reference type is invalid.
• Reference type ' ' is invalid.
• Type is invalid.
• The reference has been released.
• Reference is invalid.

AI-assisted analysis of EllanJiang/GameFramework@d0c010b051 (2026-09-15). Data as JSON: /api/errors/a37d8299ccf766fe. Report an issue: GitHub.

Appendix: source

Thrown at GameFramework/Base/ReferencePool/ReferencePool.cs:196

            InternalCheckReferenceType(referenceType);
            GetReferenceCollection(referenceType).RemoveAll();
        }

        private static void InternalCheckReferenceType(Type referenceType)
        {
            if (!m_EnableStrictCheck)
            {
                return;
            }

            if (referenceType == null)
            {
                throw new GameFrameworkException("Reference type is invalid.");
            }

            if (!referenceType.IsClass || referenceType.IsAbstract)
            {
                throw new GameFrameworkException("Reference type is not a non-abstract class type.");
            }

            if (!typeof(IReference).IsAssignableFrom(referenceType))
            {
                throw new GameFrameworkException(Utility.Text.Format("Reference type '{0}' is invalid.", referenceType.FullName));
            }
        }

        private static ReferenceCollection GetReferenceCollection(Type referenceType)
        {
            if (referenceType == null)
            {
                throw new GameFrameworkException("ReferenceType is invalid.");
            }

            ReferenceCollection referenceCollection = null;
            lock (s_ReferenceCollections)
            {

View on GitHub (pinned to d0c010b051)