diff --git a/src/BedrockBoot.Core/Global/PathsList.cs b/src/BedrockBoot.Core/Global/PathsList.cs
index fe23947c..dc9bbc9b 100644
--- a/src/BedrockBoot.Core/Global/PathsList.cs
+++ b/src/BedrockBoot.Core/Global/PathsList.cs
@@ -52,6 +52,14 @@ public static readonly string
     
     public static readonly string NeoProtonPath = Path.Combine(RootConfigPath, "BedrockBoot.Linux", "xuserProject");
     public static readonly string PreFixPath = Path.Combine(ProtonPath, "game_prefix");
+
+    /// <summary>
+    ///     真实 Wine 前缀目录。
+    ///     Proton/umu 以 STEAM_COMPAT_DATA_PATH/pfx 作为前缀（STEAM_COMPAT_DATA_PATH 即 PreFixPath），
+    ///     而 PreFixPath 自身只是 compat data 目录，里面没有 drive_c/system.reg。
+    ///     因此注册表改动、cryptbase、GameInput、wineboot 都必须作用于 WinePrefixPath。
+    /// </summary>
+    public static readonly string WinePrefixPath = Path.Combine(PreFixPath, "pfx");
     public static readonly string GamePatch = Path.Combine(NeoProtonPath, "GamePatch");
 
     public static readonly string EasyTierPath = Path.Combine(PaperConnectPath, "EasyTier");
diff --git a/src/BedrockBoot.Core/Models/Download/MultiThreadDownloader.cs b/src/BedrockBoot.Core/Models/Download/MultiThreadDownloader.cs
index 05bbf6db..ff060dbf 100644
--- a/src/BedrockBoot.Core/Models/Download/MultiThreadDownloader.cs
+++ b/src/BedrockBoot.Core/Models/Download/MultiThreadDownloader.cs
@@ -193,7 +193,19 @@ public async Task<bool> DownloadAsync(string url, string filePath, IProgress<Dow
             if (fileSize > 0 && supportsRange)
             {
                 Console.WriteLine($@"服务器支持断点续传且文件大小已知 ({fileSize} bytes)，使用多线程下载...");
-                await DownloadMultiPartAsync(uri, filePath, fileSize, progress, cancellationToken);
+                try
+                {
+                    await DownloadMultiPartAsync(uri, filePath, fileSize, progress, cancellationToken);
+                }
+                catch (RangeNotHonoredException ex)
+                {
+                    // 有些镜像（例如 gh-proxy 系代理）会声称支持 Range，实际却忽略 Range
+                    // 直接返回整份文件，多线程合并结果必然损坏 —— 必须回退单线程，
+                    // 绝不能把拼错的坏文件留在目标路径上。
+                    Console.WriteLine($@"多线程下载不可用（{ex.Message}），回退单线程下载...");
+                    TryDelete(filePath);
+                    await DownloadSinglePartAsync(uri, filePath, fileSize, progress, cancellationToken);
+                }
             }
             else if (fileSize > 0 && !supportsRange)
             {
@@ -301,9 +313,10 @@ await DownloadPartWithRetryAsync(
                 /* 忽略取消异常 */
             }
 
-            // 合并临时文件
+            // 合并临时文件（同时校验分段长度与总长度）
             Console.WriteLine(@"开始合并临时文件...");
-            await MergeTempFilesAsync(tempFiles, filePath, cancellationToken);
+            await MergeTempFilesAsync(tempFiles, parts.Select(p => p.End - p.Start + 1).ToArray(), fileSize,
+                filePath, cancellationToken);
 
             // 报告最终进度
             progressManager.ReportFinalProgress();
@@ -336,6 +349,12 @@ await DownloadPartAsync(uri, start, end, tempFilePath, partIndex,
                     downloadInfo, progressManager, cancellationToken);
                 return;
             }
+            // 服务器不按 Range 返回属于协议级问题，重试没有意义：
+            // 直接向上抛，由 DownloadAsync 回退到单线程下载。
+            catch (RangeNotHonoredException)
+            {
+                throw;
+            }
             catch (Exception ex) when (retry < maxRetries)
             {
                 Console.WriteLine($@"分段 {partIndex} 下载失败，第 {retry + 1} 次重试: {ex.Message}");
@@ -375,7 +394,18 @@ private async Task DownloadPartAsync(Uri uri, long start, long end,
 
         using var response =
             await partHttpClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
-        response.EnsureSuccessStatusCode();
+
+        // 分段必须由服务器以 206 Partial Content + 匹配的 Content-Range 回应。
+        // 若服务器忽略 Range 返回 200（整份文件），每个分段都会写入整份数据，
+        // 合并后一定是坏文件（历史 bug：862,210,941 字节的包被拼成 1,508,869,147 字节）。
+        if (response.StatusCode != HttpStatusCode.PartialContent)
+            throw new RangeNotHonoredException(
+                $"服务器未按 Range 返回分段 {partIndex}（HTTP {(int)response.StatusCode}）");
+
+        var contentRange = response.Content.Headers.ContentRange;
+        if (contentRange == null || contentRange.From != start || contentRange.To != end)
+            throw new RangeNotHonoredException(
+                $"分段 {partIndex} 的 Content-Range 不符（请求 {start}-{end}，返回 {contentRange?.ToString() ?? "空"}）");
 
         using var responseStream = await response.Content.ReadAsStreamAsync(cancellationToken);
         using var fileStream = new FileStream(tempFilePath, FileMode.Create, FileAccess.Write, FileShare.None,
@@ -414,6 +444,11 @@ private async Task DownloadPartAsync(Uri uri, long start, long end,
             }
         }
 
+        var expectedBytes = end - start + 1;
+        if (partDownloaded != expectedBytes)
+            throw new RangeNotHonoredException(
+                $"分段 {partIndex} 长度不符（收到 {partDownloaded}，应为 {expectedBytes}）");
+
         Console.WriteLine($@"分段 {partIndex} 下载完成: {partDownloaded} bytes, 耗时: {stopwatch.Elapsed.TotalSeconds:F2}s");
     }
 
@@ -512,6 +547,12 @@ await DownloadPartAsync(uri, start, end, tempFilePath, partIndex,
                     downloadInfo, totalDownloadedBytes, reportProgress, cancellationToken);
                 return;
             }
+            // 服务器不按 Range 返回属于协议级问题，重试没有意义：
+            // 直接向上抛，由 DownloadAsync 回退到单线程下载。
+            catch (RangeNotHonoredException)
+            {
+                throw;
+            }
             catch (Exception ex) when (retry < maxRetries)
             {
                 Console.WriteLine($@"分段 {partIndex} 下载失败，第 {retry + 1} 次重试: {ex.Message}");
@@ -549,7 +590,18 @@ private async Task DownloadPartAsync(Uri uri, long start, long end,
 
         using var response =
             await partHttpClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
-        response.EnsureSuccessStatusCode();
+
+        // 分段必须由服务器以 206 Partial Content + 匹配的 Content-Range 回应。
+        // 若服务器忽略 Range 返回 200（整份文件），每个分段都会写入整份数据，
+        // 合并后一定是坏文件（历史 bug：862,210,941 字节的包被拼成 1,508,869,147 字节）。
+        if (response.StatusCode != HttpStatusCode.PartialContent)
+            throw new RangeNotHonoredException(
+                $"服务器未按 Range 返回分段 {partIndex}（HTTP {(int)response.StatusCode}）");
+
+        var contentRange = response.Content.Headers.ContentRange;
+        if (contentRange == null || contentRange.From != start || contentRange.To != end)
+            throw new RangeNotHonoredException(
+                $"分段 {partIndex} 的 Content-Range 不符（请求 {start}-{end}，返回 {contentRange?.ToString() ?? "空"}）");
 
         using var responseStream = await response.Content.ReadAsStreamAsync(cancellationToken);
         using var fileStream = new FileStream(tempFilePath, FileMode.Create, FileAccess.Write, FileShare.None,
@@ -590,6 +642,11 @@ private async Task DownloadPartAsync(Uri uri, long start, long end,
             reportProgress(false);
         }
 
+        var expectedBytes = end - start + 1;
+        if (partDownloaded != expectedBytes)
+            throw new RangeNotHonoredException(
+                $"分段 {partIndex} 长度不符（收到 {partDownloaded}，应为 {expectedBytes}）");
+
         Console.WriteLine($@"分段 {partIndex} 下载完成: {partDownloaded} bytes, 耗时: {stopwatch.Elapsed.TotalSeconds:F2}s");
     }
 
@@ -624,9 +681,13 @@ private async Task DownloadSinglePartAsync(Uri uri, string filePath, long fileSi
             await _httpClient.GetAsync(uri, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
         response.EnsureSuccessStatusCode();
 
+        // 同样先写 .part，长度校验通过后再原子替换，避免留下半个文件
+        var partPath = filePath + ".part";
+        TryDelete(partPath);
+
         using var responseStream = await response.Content.ReadAsStreamAsync(cancellationToken);
         using var fileStream =
-            new FileStream(filePath, FileMode.Create, FileAccess.Write, FileShare.None, _bufferSize, true);
+            new FileStream(partPath, FileMode.Create, FileAccess.Write, FileShare.None, _bufferSize, true);
 
         var buffer = new byte[_bufferSize];
         int bytesRead;
@@ -647,11 +708,29 @@ void ReportProgressIfNeeded()
             }
         }
 
-        while ((bytesRead = await responseStream.ReadAsync(buffer, cancellationToken)) > 0)
+        try
         {
-            await fileStream.WriteAsync(buffer.AsMemory(0, bytesRead), cancellationToken);
-            totalBytesRead += bytesRead;
-            ReportProgressIfNeeded();
+            while ((bytesRead = await responseStream.ReadAsync(buffer, cancellationToken)) > 0)
+            {
+                await fileStream.WriteAsync(buffer.AsMemory(0, bytesRead), cancellationToken);
+                totalBytesRead += bytesRead;
+                ReportProgressIfNeeded();
+            }
+
+            fileStream.Flush();
+
+            if (fileSize > 0 && totalBytesRead != fileSize)
+                throw new RangeNotHonoredException(
+                    $"下载长度不符（收到 {totalBytesRead}，应为 {fileSize}），已丢弃不完整文件");
+
+            fileStream.Close();
+            File.Move(partPath, filePath, true);
+        }
+        catch
+        {
+            fileStream.Close();
+            TryDelete(partPath);
+            throw;
         }
 
         progress?.Report(new DownloadProgress
@@ -668,9 +747,12 @@ private async Task DownloadAsStreamAsync(Uri uri, string filePath, IProgress<Dow
             await _httpClient.GetAsync(uri, HttpCompletionOption.ResponseHeadersRead, cancellationToken);
         response.EnsureSuccessStatusCode();
 
+        var partPath = filePath + ".part";
+        TryDelete(partPath);
+
         using var responseStream = await response.Content.ReadAsStreamAsync(cancellationToken);
         using var fileStream =
-            new FileStream(filePath, FileMode.Create, FileAccess.Write, FileShare.None, _bufferSize, true);
+            new FileStream(partPath, FileMode.Create, FileAccess.Write, FileShare.None, _bufferSize, true);
 
         var buffer = new byte[_bufferSize];
         int bytesRead;
@@ -691,11 +773,24 @@ void ReportProgressIfNeeded()
             }
         }
 
-        while ((bytesRead = await responseStream.ReadAsync(buffer, cancellationToken)) > 0)
+        try
         {
-            await fileStream.WriteAsync(buffer.AsMemory(0, bytesRead), cancellationToken);
-            totalBytesRead += bytesRead;
-            ReportProgressIfNeeded();
+            while ((bytesRead = await responseStream.ReadAsync(buffer, cancellationToken)) > 0)
+            {
+                await fileStream.WriteAsync(buffer.AsMemory(0, bytesRead), cancellationToken);
+                totalBytesRead += bytesRead;
+                ReportProgressIfNeeded();
+            }
+
+            fileStream.Flush();
+            fileStream.Close();
+            File.Move(partPath, filePath, true);
+        }
+        catch
+        {
+            fileStream.Close();
+            TryDelete(partPath);
+            throw;
         }
 
         progress?.Report(new DownloadProgress
@@ -705,7 +800,8 @@ void ReportProgressIfNeeded()
         });
     }
 
-    private async Task MergeTempFilesAsync(string[] tempFiles, string outputPath, CancellationToken cancellationToken)
+    private async Task MergeTempFilesAsync(string[] tempFiles, long[] expectedPartSizes, long expectedFileSize,
+        string outputPath, CancellationToken cancellationToken)
     {
         await Task.Delay(1000, cancellationToken);
 
@@ -715,40 +811,94 @@ private async Task MergeTempFilesAsync(string[] tempFiles, string outputPath, Ca
             throw new FileNotFoundException(
                 $"合并临时文件失败: 缺失 {missingFiles.Length} 个分段文件: {string.Join(", ", missingFiles)}");
 
+        // 逐段核对长度：任一分段长度不对（例如服务器忽略了 Range），合并结果必坏
+        for (var i = 0; i < tempFiles.Length; i++)
+        {
+            var actual = new FileInfo(tempFiles[i]).Length;
+            var expected = i < expectedPartSizes.Length ? expectedPartSizes[i] : -1;
+            if (expected >= 0 && actual != expected)
+                throw new RangeNotHonoredException(
+                    $"分段 {i} 长度不符（{actual}，应为 {expected}），拒绝合并损坏文件");
+        }
+
+        // 先写到 .part，校验总长度后再原子替换目标文件 —— 保证目标路径上只会出现完整文件
+        var partPath = outputPath + ".part";
+        TryDelete(partPath);
+
         // 增加缓冲区大小
         const int largeBufferSize = 81920 * 4; // 320KB缓冲区
 
-        using var outputStream = new BufferedStream(
-            new FileStream(outputPath, FileMode.Create, FileAccess.Write,
-                FileShare.None, largeBufferSize, FileOptions.WriteThrough | FileOptions.Asynchronous),
-            largeBufferSize * 2);
+        try
+        {
+            using (var outputStream = new BufferedStream(
+                       new FileStream(partPath, FileMode.Create, FileAccess.Write,
+                           FileShare.None, largeBufferSize, FileOptions.WriteThrough | FileOptions.Asynchronous),
+                       largeBufferSize * 2))
+            {
+                // 按顺序处理文件
+                var sortedFiles = tempFiles
+                    .Select(f => new FileInfo(f))
+                    .ToArray();
+
+                foreach (var fileInfo in sortedFiles)
+                {
+                    cancellationToken.ThrowIfCancellationRequested();
 
-        // 按顺序处理文件
-        var sortedFiles = tempFiles
-            .Select(f => new FileInfo(f))
-            .ToArray();
+                    Console.WriteLine($@"正在合并文件: {fileInfo.FullName}, 大小: {fileInfo.Length} bytes");
 
-        foreach (var fileInfo in sortedFiles)
-        {
-            cancellationToken.ThrowIfCancellationRequested();
+                    using var inputStream = new BufferedStream(
+                        new FileStream(fileInfo.FullName, FileMode.Open,
+                            FileAccess.Read, FileShare.Read, largeBufferSize,
+                            FileOptions.SequentialScan | FileOptions.Asynchronous),
+                        largeBufferSize * 2);
 
-            Console.WriteLine($@"正在合并文件: {fileInfo.FullName}, 大小: {fileInfo.Length} bytes");
+                    var buffer = new byte[largeBufferSize];
+                    int bytesRead;
 
-            using var inputStream = new BufferedStream(
-                new FileStream(fileInfo.FullName, FileMode.Open,
-                    FileAccess.Read, FileShare.Read, largeBufferSize,
-                    FileOptions.SequentialScan | FileOptions.Asynchronous),
-                largeBufferSize * 2);
+                    // 手动复制以支持进度报告
+                    while ((bytesRead = await inputStream.ReadAsync(buffer, 0, buffer.Length, cancellationToken)) > 0)
+                        await outputStream.WriteAsync(buffer, 0, bytesRead, cancellationToken);
+                }
+
+                await outputStream.FlushAsync(cancellationToken);
+            }
 
-            var buffer = new byte[largeBufferSize];
-            int bytesRead;
+            var mergedSize = new FileInfo(partPath).Length;
+            if (expectedFileSize > 0 && mergedSize != expectedFileSize)
+                throw new RangeNotHonoredException(
+                    $"合并结果长度不符（{mergedSize}，应为 {expectedFileSize}），已丢弃损坏文件");
 
-            // 手动复制以支持进度报告
-            while ((bytesRead = await inputStream.ReadAsync(buffer, 0, buffer.Length, cancellationToken)) > 0)
-                await outputStream.WriteAsync(buffer, 0, bytesRead, cancellationToken);
+            File.Move(partPath, outputPath, true);
         }
+        catch
+        {
+            TryDelete(partPath);
+            throw;
+        }
+    }
 
-        await outputStream.FlushAsync(cancellationToken);
+    /// <summary>删除文件并忽略错误（用于清理损坏/临时产物）。</summary>
+    private static void TryDelete(string path)
+    {
+        try
+        {
+            if (File.Exists(path)) File.Delete(path);
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($@"删除文件失败 {path}: {ex.Message}");
+        }
+    }
+
+    /// <summary>
+    ///     服务器未按请求的 Range 返回数据（例如忽略 Range 直接返回整份文件）。
+    ///     出现该异常时必须回退单线程下载，否则合并结果必然损坏。
+    /// </summary>
+    private sealed class RangeNotHonoredException : Exception
+    {
+        public RangeNotHonoredException(string message) : base(message)
+        {
+        }
     }
 
     private void CleanupTempFiles(string[] tempFiles)
diff --git a/src/BedrockBoot.Linux/Models/Game/EasyLauncher.cs b/src/BedrockBoot.Linux/Models/Game/EasyLauncher.cs
index ee6e8b6c..3b16d1f9 100644
--- a/src/BedrockBoot.Linux/Models/Game/EasyLauncher.cs
+++ b/src/BedrockBoot.Linux/Models/Game/EasyLauncher.cs
@@ -468,7 +468,7 @@ private bool PrepareNeoLaunchEnvironment()
         }
 
         ProtonPatcher.Patch(ProtonNeoCore.ProtonRootPath);
-        GameInputInstaller.Install(PathsList.PreFixPath, VersionInfo.VersionPath);
+        GameInputInstaller.Install(PathsList.WinePrefixPath, VersionInfo.VersionPath);
 
         GdkFixups.PatchLhcXcurlGate(VersionInfo.VersionPath);
         GdkFixups.BumpStackReserve(Path.Combine(VersionInfo.VersionPath, VersionInfo.BodyFile));
@@ -485,7 +485,7 @@ private void EnsureGameInputInstalled()
         var protonConfig = ProtonCore.GetVersionConfig(_linuxLaunchInfo!.ProtonPath);
 
         bool isInstalled = VersionInfo.VersionStatus.GameInputInstalled
-                           && Path.Exists(_linuxLaunchInfo.PrefixPath)
+                           && Path.Exists(PathsList.WinePrefixPath)
                            && protonConfig.IsGameInputInstalled;
 
         if (isInstalled) return;
@@ -501,7 +501,7 @@ private void EnsureGameInputInstalled()
         }
         else
         {
-            if (!InstallGameInputWithWine(PathsList.PreFixPath, msiPath)) return;
+            if (!InstallGameInputWithWine(PathsList.WinePrefixPath, msiPath)) return;
         }
 
         Console.WriteLine("GameInput 安装完毕");
@@ -562,7 +562,7 @@ private static void InstallCryptbase()
         {
             var builtin = Path.Combine(ProtonNeoCore.ProtonRootPath, "files", "lib", "wine", "x86_64-windows",
                 "cryptbase.dll");
-            var dst = Path.Combine(PathsList.PreFixPath, "drive_c", "windows", "system32", "cryptbase.dll");
+            var dst = Path.Combine(PathsList.WinePrefixPath, "drive_c", "windows", "system32", "cryptbase.dll");
 
             if (File.Exists(builtin) && !File.Exists(dst))
             {
diff --git a/src/BedrockBoot.Linux/Models/Pack/Wine/WinePrefix.cs b/src/BedrockBoot.Linux/Models/Pack/Wine/WinePrefix.cs
index 35ea414d..d7ac7e06 100644
--- a/src/BedrockBoot.Linux/Models/Pack/Wine/WinePrefix.cs
+++ b/src/BedrockBoot.Linux/Models/Pack/Wine/WinePrefix.cs
@@ -47,7 +47,7 @@ public static bool IsReady(string prefix)
 
     public static bool Boot()
     {
-        var pfx = PathsList.PreFixPath;
+        var pfx = PathsList.WinePrefixPath;
         if (IsReady(pfx))
         {
             Console.WriteLine("Wine prefix ready");
@@ -64,6 +64,11 @@ public static bool Boot()
             UseShellExecute = false,
         };
         psi.EnvironmentVariables["WINEPREFIX"] = pfx;
+        // proton 脚本要求 STEAM_COMPAT_DATA_PATH（前缀会被解析为 <它>/pfx），
+        // 以及 STEAM_COMPAT_CLIENT_INSTALL_PATH；缺任一个都会直接报错退出。
+        psi.EnvironmentVariables["STEAM_COMPAT_DATA_PATH"] = PathsList.PreFixPath;
+        psi.EnvironmentVariables["STEAM_COMPAT_CLIENT_INSTALL_PATH"] =
+            Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.UserProfile), ".steam", "steam");
         psi.EnvironmentVariables["WINEDEBUG"] = "-all";
         psi.EnvironmentVariables["SDL_VIDEODRIVER"] = "dummy";
 
@@ -131,27 +136,31 @@ public static void ApplyWinegdkPrereqs()
 
         var user = new List<RegChange>
         {
+            // Wine 内置的 amd_ags_x64 无法从自身 PE 读出 AGS 版本号（err 1812），
+            // 游戏（RenderDragon）会因此反复调用 agsInit 死循环：窗口白屏、主线程 100% CPU、无响应。
+            // 直接禁用该 DLL，游戏会走「没有 AGS」的普通分支（本地 AMD 机器不加载它也能正常运行）。
+            WineRegistry.RegSz(@"Software\Wine\DllOverrides", "amd_ags_x64", "disabled"),
             WineRegistry.RegSz("Environment", "MICROSOFT_WINDOWSAPPRUNTIME_BOOTSTRAP_INITIALIZE_SHOWUI", "0"),
             WineRegistry.RegSz("Environment", "MICROSOFT_WINDOWSAPPRUNTIME_BOOTSTRAP_INITIALIZE_FAILFAST", "0"),
             WineRegistry.RegSz("Environment", "MICROSOFT_WINDOWSAPPRUNTIME_DEPLOYMENT_INITIALIZE_ONERRORSHOWUI", "0"),
         };
 
-        WineRegistry.UpdatePrefix(PathsList.PreFixPath, machine.ToArray(), user.ToArray());
+        WineRegistry.UpdatePrefix(PathsList.WinePrefixPath, machine.ToArray(), user.ToArray());
         Console.WriteLine("WineGDK prereqs applied");
     }
 
     public static void SetRefreshToken(string token)
     {
-        WineRegistry.UpdatePrefix(PathsList.PreFixPath,
+        WineRegistry.UpdatePrefix(PathsList.WinePrefixPath,
             machine: new[] { WineRegistry.RegSz(PathsList.WinegdkReg, "RefreshToken", token) });
         Console.WriteLine("Refresh token written to Wine registry");
     }
 
     public static void RemoveRefreshToken()
     {
-        var systemReg = Path.Combine(PathsList.PreFixPath, "system.reg");
+        var systemReg = Path.Combine(PathsList.WinePrefixPath, "system.reg");
         if (!File.Exists(systemReg)) return;
-        WineRegistry.UpdatePrefix(PathsList.PreFixPath,
+        WineRegistry.UpdatePrefix(PathsList.WinePrefixPath,
             machine: new[] { WineRegistry.RegDelete(PathsList.WinegdkReg, "RefreshToken") });
     }
 }
\ No newline at end of file