在 IIS 上使用文件助手时出错；有时：S：[PolicyException：无法获得所需的权限。]答案

【问题标题】：error when using filehelpers on IIS; sometimes :S : [PolicyException: Required permissions cannot be acquired.]在 IIS 上使用文件助手时出错；有时：S：[PolicyException：无法获得所需的权限。]
【发布时间】：2009-12-08 19:22:02
【问题描述】：

FileHelpers.dll (2.0) 在我的解决方案中的 2 个类库（Dto 和服务）中被引用
我的 webapp（asp.net mvc）在 IIS7（完全信任）Windows 7 PRO 64 上，从 VS2008 启动我的应用程序时有时会出现此异常：（为了摆脱它，我从 bin 中删除 FileHelpers.dll，运行，关闭浏览器，重建解决方案并再次运行）

     [PolicyException: Required permissions cannot be acquired.]
       System.Security.SecurityManager.ResolvePolicy(Evidence evidence, PermissionSet reqdPset, PermissionSet optPset, PermissionSet denyPset, PermissionSet& denied, Boolean checkExecutionPermission) +10238142
       System.Security.SecurityManager.ResolvePolicy(Evidence evidence, PermissionSet reqdPset, PermissionSet optPset, PermissionSet denyPset, PermissionSet& denied, Int32& securitySpecialFlags, Boolean checkExecutionPermission) +97

    [FileLoadException: Could not load file or assembly 'FileHelpers, Version=2.0.0.0, Culture=neutral, PublicKeyToken=3e0c08d59cc3d657' or one of its dependencies. Failed to grant minimum permission requests. (Exception from HRESULT: 0x80131417)]
       System.Reflection.Assembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection) +0
       System.Reflection.Assembly.InternalLoad(AssemblyName assemblyRef, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) +416
       System.Reflection.Assembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) +166
       System.Reflection.Assembly.Load(String assemblyString) +35
       System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +190

    [ConfigurationErrorsException: Could not load file or assembly 'FileHelpers, Version=2.0.0.0, Culture=neutral, PublicKeyToken=3e0c08d59cc3d657' or one of its dependencies. Failed to grant minimum permission requests. (Exception from HRESULT: 0x80131417)]
       System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +11207304
       System.Web.Configuration.CompilationSection.LoadAllAssembliesFromAppDomainBinDirectory() +388
       System.Web.Configuration.CompilationSection.LoadAssembly(AssemblyInfo ai) +232
       System.Web.Configuration.AssemblyInfo.get_AssemblyInternal() +48
       System.Web.Compilation.BuildManager.GetReferencedAssemblies(CompilationSection compConfig) +210
       System.Web.Compilation.BuildProvidersCompiler..ctor(VirtualPath configPath, Boolean supportLocalization, String outputAssemblyName) +76
       System.Web.Compilation.ApplicationBuildProvider.GetGlobalAsaxBuildResult(Boolean isPrecompiledApp) +283
       System.Web.Compilation.BuildManager.CompileGlobalAsax() +50
       System.Web.Compilation.BuildManager.EnsureTopLevelFilesCompiled() +676

    [HttpException (0x80004005): Could not load file or assembly 'FileHelpers, Version=2.0.0.0, Culture=neutral, PublicKeyToken=3e0c08d59cc3d657' or one of its dependencies. Failed to grant minimum permission requests. (Exception from HRESULT: 0x80131417)]
       System.Web.Compilation.BuildManager.ReportTopLevelCompilationException() +76
       System.Web.Compilation.BuildManager.EnsureTopLevelFilesCompiled() +1012
       System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters) +1025

[HttpException (0x80004005): Could not load file or assembly 'FileHelpers, Version=2.0.0.0, Culture=neutral, PublicKeyToken=3e0c08d59cc3d657' or one of its dependencies. Failed to grant minimum permission requests. (Exception from HRESULT: 0x80131417)]
   System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +11301302
   System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +88
   System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +4338644

我尝试切换到不使用反射的 FileHelpers 1.6，但出现此异常：

    Stack Trace: 


[PolicyException: Required permissions cannot be acquired.]
   System.Security.SecurityManager.ResolvePolicy(Evidence evidence, PermissionSet reqdPset, PermissionSet optPset, PermissionSet denyPset, PermissionSet& denied, Boolean checkExecutionPermission) +10238142
   System.Security.SecurityManager.ResolvePolicy(Evidence evidence, PermissionSet reqdPset, PermissionSet optPset, PermissionSet denyPset, PermissionSet& denied, Int32& securitySpecialFlags, Boolean checkExecutionPermission) +97

[FileLoadException: Could not load file or assembly 'FileHelpers, Version=1.6.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. Failed to grant minimum permission requests. (Exception from HRESULT: 0x80131417)]
   System.Reflection.Assembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection) +0
   System.Reflection.Assembly.InternalLoad(AssemblyName assemblyRef, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) +416
   System.Reflection.Assembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) +166
   System.Reflection.Assembly.Load(String assemblyString) +35
   System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +190

[ConfigurationErrorsException: Could not load file or assembly 'FileHelpers, Version=1.6.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. Failed to grant minimum permission requests. (Exception from HRESULT: 0x80131417)]
   System.Web.Configuration.CompilationSection.LoadAssemblyHelper(String assemblyName, Boolean starDirective) +11207304
   System.Web.Configuration.CompilationSection.LoadAllAssembliesFromAppDomainBinDirectory() +388
   System.Web.Configuration.CompilationSection.LoadAssembly(AssemblyInfo ai) +232
   System.Web.Configuration.AssemblyInfo.get_AssemblyInternal() +48
   System.Web.Compilation.BuildManager.GetReferencedAssemblies(CompilationSection compConfig) +210
   System.Web.Compilation.BuildProvidersCompiler..ctor(VirtualPath configPath, Boolean supportLocalization, String outputAssemblyName) +76
   System.Web.Compilation.ApplicationBuildProvider.GetGlobalAsaxBuildResult(Boolean isPrecompiledApp) +283
   System.Web.Compilation.BuildManager.CompileGlobalAsax() +50
   System.Web.Compilation.BuildManager.EnsureTopLevelFilesCompiled() +676

[HttpException (0x80004005): Could not load file or assembly 'FileHelpers, Version=1.6.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. Failed to grant minimum permission requests. (Exception from HRESULT: 0x80131417)]
   System.Web.Compilation.BuildManager.ReportTopLevelCompilationException() +76
   System.Web.Compilation.BuildManager.EnsureTopLevelFilesCompiled() +1012
   System.Web.Hosting.HostingEnvironment.Initialize(ApplicationManager appManager, IApplicationHost appHost, IConfigMapPathFactory configMapPathFactory, HostingEnvironmentParameters hostingParameters) +1025

[HttpException (0x80004005): Could not load file or assembly 'FileHelpers, Version=1.6.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. Failed to grant minimum permission requests. (Exception from HRESULT: 0x80131417)]
   System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +11301302
   System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +88
   System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +4338644

【问题讨论】：

根据您提到的“完全信任”这一事实，您正在寻找解决方案的正确轨道，因为该错误确实看起来像运行时未能授予 FileHelpers 必要的反射权限，这是只应该在部分信任配置下发生的事情。是仅在通过 VS 调试时发生，还是在直接通过浏览器加载网站时发生（即直接转到 localhost/myapp）？
我在直接加载网站时没有尝试这样做，我会尝试和您联系，但是在VS中要摆脱这个错误，我必须从文件中删除FileHelpers.dll WebUI/bin，运行webapp，关闭浏览器，停止webapp，重建（在bin中创建FileHelpers.dll）并再次运行
如果我在删除 dll 后立即重建，它将无法正常工作
所以我试了一下，不管你是从VS运行还是直接运行，如果最后一次在VS中不起作用，那么直接在它不起作用
我切换到 FileHelpers 1.6 仍然有同样的问题

标签： asp.net asp.net-mvc security iis filehelpers

【解决方案1】：

这里有点暗中的刺，但尝试三件事：

在 IIS 管理器中，找到运行应用程序的应用程序池并打开高级设置。确保“启用 32 位应用程序”设置为 true。
确保您以管理员身份运行 Visual Studio。
在解决方案资源管理器中检查您的子项目的引用。尝试将 FileHelpers 的引用上的“复制本地”属性设置为 false。您可能需要直接在您的 Web 项目中添加对该程序集的引用，然后将本地复制设置为 true。（我已经看到两个子项目试图将相同的引用 DLL 推送到单个 Web 应用程序可能会导致有趣的副作用）。还要确保两个子项目从相同的物理位置引用完全相同的 FileHelpers 程序集。

【讨论】：

第一个提示加 1。我有同样的问题，它解决了这个问题。

【解决方案2】：

试试这个：加载 .NET 配置向导/工具（开始 > 控制面板 > 管理工具 > .NET 配置）

单击运行时安全策略

在右侧面板中选择“调整区域安全”..

如果您加载的 DLL 不在本地硬盘驱动器上，也很常见。如果文件位于文件服务器等上，请将其移动到 C: 某处..

【讨论】：

【解决方案3】：

重新安装windows、IIS、VS后问题就消失了，所以我现在真的不知道为什么会出现这个问题

【讨论】：

看这里：meta.stackexchange.com/questions/37328/…，明天一切都会好起来的