What causes "Unload scene success callback is invalid." in EllanJiang/GameFramework?

Provide a valid UnloadSceneSuccessCallback delegate to the constructor

EllanJiang/GameFramework · error · GameFrameworkException

Unload scene success callback is invalid.

Error message

Unload scene success callback is invalid.

What it means

The UnloadSceneCallbacks constructor requires a non-null unload-scene success callback; the failure callback may be omitted but the success callback is mandatory. Passing null means the framework could not notify the caller when a scene finishes unloading, so it throws immediately. This is a fail-fast argument check.

Solutions

Provide a valid UnloadSceneSuccessCallback delegate to the constructor
Check that the method assigned to the success callback is not conditionally null
Only construct UnloadSceneCallbacks after the handler is assigned

Example fix

// before
new UnloadSceneCallbacks(null, OnUnloadSceneFailure);
// after
new UnloadSceneCallbacks(OnUnloadSceneSuccess, OnUnloadSceneFailure);

Defensive patterns

Strategy: validation

Validate before calling

if (onSuccess == null) { Log.Error("Unload scene success callback required"); return; }

Type guard

bool HasSuccessCallback(UnloadSceneSuccessCallback cb) => cb != null;

Try / catch

try { var cbs = new UnloadSceneCallbacks(onSuccess, onFailure); } catch (GameFrameworkException ex) when (ex.Message == "Unload scene success callback is invalid.") { Log.Error(ex, "Missing success callback"); }

Prevention

Never pass nullable delegates to callback bundle constructors
Assign handler methods before constructing the callbacks object
Prefer method groups over conditionally-initialized delegate fields

When it happens

Trigger: Constructing UnloadSceneCallbacks with null for the unloadSceneSuccessCallback parameter, e.g. when passing callbacks to ResourceManager's UnloadScene API.

Common situations: Passing an uninitialized delegate/method-group reference, a conditional callback that was never assigned, or copying callback-creation code and leaving the success handler out.

Related errors

AI-assisted analysis of EllanJiang/GameFramework@d0c010b051 (2026-09-15). Data as JSON: /api/errors/2a270af7830b3c5a. Report an issue: GitHub.

Appendix: source

Thrown at GameFramework/Resource/UnloadSceneCallbacks.cs:36

        /// <summary>
        /// 初始化卸载场景回调函数集的新实例。
        /// </summary>
        /// <param name="unloadSceneSuccessCallback">卸载场景成功回调函数。</param>
        public UnloadSceneCallbacks(UnloadSceneSuccessCallback unloadSceneSuccessCallback)
            : this(unloadSceneSuccessCallback, null)
        {
        }

        /// <summary>
        /// 初始化卸载场景回调函数集的新实例。
        /// </summary>
        /// <param name="unloadSceneSuccessCallback">卸载场景成功回调函数。</param>
        /// <param name="unloadSceneFailureCallback">卸载场景失败回调函数。</param>
        public UnloadSceneCallbacks(UnloadSceneSuccessCallback unloadSceneSuccessCallback, UnloadSceneFailureCallback unloadSceneFailureCallback)
        {
            if (unloadSceneSuccessCallback == null)
            {
                throw new GameFrameworkException("Unload scene success callback is invalid.");
            }

            m_UnloadSceneSuccessCallback = unloadSceneSuccessCallback;
            m_UnloadSceneFailureCallback = unloadSceneFailureCallback;
        }

        /// <summary>
        /// 获取卸载场景成功回调函数。
        /// </summary>
        public UnloadSceneSuccessCallback UnloadSceneSuccessCallback
        {
            get
            {
                return m_UnloadSceneSuccessCallback;
            }
        }

        /// <summary>

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