egametang/ET · error · Exception

iScene cant set null: {this.GetType().FullName}

Error message

iScene cant set null: {this.GetType().FullName}

What it means

Thrown by the Entity.IScene setter when assigning null. Every entity must belong to exactly one scene; null is never valid. Removing an entity from its scene is done by Dispose, not by clearing IScene.

Source

Thrown at Packages/cn.etetet.core/Scripts/Core/Share/Entity/Entity.cs:327

        [BsonId]
        public long Id { get; protected set; }

        [BsonIgnore]
        protected IScene iScene;

        [MemoryPackIgnore]
        [BsonIgnore]
        public IScene IScene
        {
            get
            {
                return this.iScene;
            }
            protected set
            {
                if (value == null)
                {
                    throw new Exception($"iScene cant set null: {this.GetType().FullName}");
                }

                if (this.iScene == value)
                {
                    return;
                }

                if (this.iScene != null)
                {
                    this.iScene = value;
                    return;
                }

                this.iScene = value;
                
                if (this.InstanceId == 0)
                {
                    this.InstanceId = iScene.Fiber.NewInstanceId();

View on GitHub (pinned to 5cab01f7a8)

Solutions

1. Never assign null to IScene; remove the entity via Dispose() instead.
2. Null-check any candidate scene before assigning.
3. Confirm the target scene object is constructed and valid before binding.

Example fix

// before
entity.IScene = newScene;   // newScene may be null

// after
if (newScene == null) throw new InvalidOperationException("scene required");
entity.IScene = newScene;

if (newScene != null)
{
    entity.IScene = newScene;
}

When it happens

Trigger: Directly assigning `entity.IScene = null`; a rebind routine that nulls the scene reference on cleanup; deserialization encountering a null scene reference.

Common situations: Tearing down a scene but nulling the property instead of disposing entities; reparent helper that resets scene to null as a reset step.

Related errors

• cant set parent because parent iSence is null: {this.GetType
• cant set parent null: {this.GetType().FullName}
• cant set parent self: {this.GetType().FullName}
• entity already has component: {type.FullName}
• entity is disposed, instanceid == 0!

AI-assisted analysis of egametang/ET@5cab01f7a8 (2026-08-13). Data as JSON: /api/errors/175796f285b15fd8. Report an issue: GitHub.