重新创建Cloud Recognition与Image Target后出现空引用异常求助

修复Image Target缩放问题时，我重新创建了Cloud Recognition GameObject和Image Target并替换了旧对象，全程未修改任何脚本，但运行时出现回调空引用异常，错误日志如下：

Exception in callback: Object reference not set to an instance of an object
UnityEngine.Debug:LogErrorFormat (string,object[])
Vuforia.Internal.Utility.UnityLogger:LogError (string,object[])
Vuforia.Internal.Utility.Log:Error (string,object[])
Vuforia.Utility.ExtensionMethods.DelegateHelper:InvokeDelegate (System.Delegate,object[])
Vuforia.Utility.ExtensionMethods.DelegateHelper:InvokeWithExceptionHandling<Vuforia.CloudRecoBehaviour/CloudRecoSearchResult> (System.Action`1<Vuforia.CloudRecoBehaviour/CloudRecoSearchResult>,Vuforia.CloudRecoBehaviour/CloudRecoSearchResult)
Vuforia.CloudRecoBehaviour/<>c__DisplayClass42_1:<OnRecoObservations>b__1 (System.Action`1<Vuforia.CloudRecoBehaviour/CloudRecoSearchResult>)
Vuforia.Internal.Utility.ExtensionMethods.IEnumerableExtensionMethods:ForEach<System.Action`1<Vuforia.CloudRecoBehaviour/CloudRecoSearchResult>> (System.Collections.Generic.IEnumerable`1<System.Action`1<Vuforia.CloudRecoBehaviour/CloudRecoSearchResult>>,System.Action`1<System.Action`1<Vuforia.CloudRecoBehaviour/CloudRecoSearchResult>>)
Vuforia.CloudRecoBehaviour/<>c__DisplayClass42_0:<OnRecoObservations>b__0 ()
Vuforia.CloudRecoBehaviour:Update ()

求遇到过类似问题的开发者提供解决方案，感谢！

内容的提问来源于stack exchange，提问作者Live Print