What causes "Download manager is invalid." in EllanJiang/GameFramework?

Create/add the DownloadManager component and pass the non-null instance

EllanJiang/GameFramework · error · GameFrameworkException

Download manager is invalid.

Error message

Download manager is invalid.

What it means

ResourceManager.SetDownloadManager throws this when the provided IDownloadManager reference is null. The updater requires a download manager to fetch remote resource updates and wires event handlers (DownloadStart/Update/Success) to it, so a null reference is rejected up front.

Solutions

Create/add the DownloadManager component and pass the non-null instance
Ensure initialization order: download manager exists and is initialized before SetDownloadManager
Verify your service locator / GetComponent call actually returns an instance

Example fix

// before
resourceManager.SetDownloadManager(m_GameEntry.GetComponent<DownloadManager>()); // null if missing
// after
var dm = m_GameEntry.GetComponent<DownloadManager>();
if (dm == null) { dm = m_GameEntry.AddComponent<DownloadManager>(); }
resourceManager.SetDownloadManager(dm);

Defensive patterns

Strategy: validation

Validate before calling

if (downloadManager == null) { downloadManager = AddOrGetComponent<DownloadManager>(); }

Type guard

bool HasDownloadManager(IDownloadManager dm) => dm != null;

Try / catch

try { resourceManager.SetDownloadManager(dm); } catch (GameFrameworkException ex) { Log.Error("DownloadManager not initialized: " + ex.Message); }

Prevention

Initialize the DownloadManager component before the ResourceManager
Verify framework component creation order in your game entry code
Assert component lookups (GetComponent) return non-null during bootstrap

When it happens

Trigger: Calling SetDownloadManager before the DownloadManager component was added/initialized, passing null explicitly, or a DI/GetComponent call that returned null (e.g. missing component on the GameObject).

Common situations: Unity initialization order issues where the resource manager is set up before the download manager; forgetting to add the DownloadManager component to the game framework GameObject; typo in component lookup.

Related errors

AI-assisted analysis of EllanJiang/GameFramework@d0c010b051 (2026-09-15). Data as JSON: /api/errors/cde1dbc35233d078. Report an issue: GitHub.

Appendix: source

Thrown at GameFramework/Resource/ResourceManager.ResourceUpdater.cs:273

                    m_DownloadManager.DownloadUpdate -= OnDownloadUpdate;
                    m_DownloadManager.DownloadSuccess -= OnDownloadSuccess;
                    m_DownloadManager.DownloadFailure -= OnDownloadFailure;
                }

                m_UpdateWaitingInfo.Clear();
                m_UpdateCandidateInfo.Clear();
                m_CachedFileSystemsForGenerateReadWriteVersionList.Clear();
            }

            /// <summary>
            /// 设置下载管理器。
            /// </summary>
            /// <param name="downloadManager">下载管理器。</param>
            public void SetDownloadManager(IDownloadManager downloadManager)
            {
                if (downloadManager == null)
                {
                    throw new GameFrameworkException("Download manager is invalid.");
                }

                m_DownloadManager = downloadManager;
                m_DownloadManager.DownloadStart += OnDownloadStart;
                m_DownloadManager.DownloadUpdate += OnDownloadUpdate;
                m_DownloadManager.DownloadSuccess += OnDownloadSuccess;
                m_DownloadManager.DownloadFailure += OnDownloadFailure;
            }

            /// <summary>
            /// 增加资源更新。
            /// </summary>
            /// <param name="resourceName">资源名称。</param>
            /// <param name="fileSystemName">资源所在的文件系统名称。</param>
            /// <param name="loadType">资源加载方式。</param>
            /// <param name="length">资源大小。</param>
            /// <param name="hashCode">资源哈希值。</param>
            /// <param name="compressedLength">压缩后大小。</param>

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