[LayaAir 2.0]box2d引擎报错问题

我做的项目是会有不断的生成预制(有RigidBody和BoxCollider)，在运动到终点时再回收到Pool中，有概率报如下错误laya.physics.js:430 Uncaught TypeError: Cannot read property 'GetType' of null
    at box2d.b2Fixture.GetType (laya.physics.js:430)
    at box2d.b2ContactFactory.Create (laya.physics.js:576)
    at box2d.b2ContactManager.AddPair (laya.physics.js:586)
    at box2d.b2BroadPhase.UpdatePairs (laya.physics.js:308)
    at box2d.b2ContactManager.FindNewContacts (laya.physics.js:584)
    at box2d.b2World.Solve (laya.physics.js:799)
    at box2d.b2World.Step (laya.physics.js:811)
    at Physics._update (laya.physics.js:2003)
    at TimerHandler.run (laya.core.js:21423)
    at Timer._update (laya.core.js:21262)
 
相关逻辑代码如下：

    moveSuccess(){

        this.owner.removeSelf();

        Laya.Pool.recover("flyCat", this.owner)

    }

    onTriggerEnter(other: any, self: any, contact: any): void {

        if (other.label === "cloud") {

            Laya.Tween.clearAll(this._sp)

            let effect: Laya.Animation = Laya.Pool.getItemByCreateFun("deathEffect", this.createEffect, this);

            effect.pos(this._sp.x, this._sp.y);

            this._sp.parent.addChild(effect);

            effect.play(0, false);

            this.owner.removeSelf();

            Laya.Pool.recover("flyCat", this.owner)

        }

    }



    createEffect(): Laya.Animation {

        let ani: Laya.Animation = new Laya.Animation();

        ani.loadAnimation("catFly.ani");

        ani.on(Laya.Event.COMPLETE, null, recover);

        function recover(): void {

            ani.removeSelf();

            Laya.Pool.recover("deathEffect", ani);

        }

        return ani;

    }