無法加載文件或程序集「System.Web」或其某個依賴項。訪問被拒絕

運行.NET Web應用程序時，我收到了一個EventLog未知的錯誤。無法加載文件或程序集「System.Web」或其某個依賴項。訪問被拒絕

該應用程序基本上讀取數據庫，然後從磁盤讀取文件大小，然後寫回到數據庫。

我已經得到了應用並用我的工作站（IISExpress）上沒有問題，我們的其他服務器（Windows 2008在IIS7）

但我對我們的IIS6 2003 R2服務器上運行它，我得到運行一些奇怪的行爲。在IIS應用程序啓動和報告沒有錯，但是當我嘗試訪問的網頁，我收到了「服務器應用程序不可用」，並在服務器上的事件日誌給了我這個轉儲：

Event Type: Error 
Event Source: ASP.NET 4.0.30319.0 
Event Category: None 
Event ID: 1325 
Date:  24.05.2011 
Time:  13:29:11 
User:  N/A 
Description: 
Failed to initialize the AppDomain:/LM/W3SVC/1309226359/Root 

Exception: System.IO.FileLoadException 

Message: Could not load file or assembly 'System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. Access is denied. 

StackTrace: at System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) 
at System.Reflection.RuntimeAssembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks) 
at System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection, Boolean suppressSecurityChecks) 
at System.Reflection.RuntimeAssembly.InternalLoad(String assemblyString, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection) 
at System.Activator.CreateInstance(String assemblyName, String typeName, Boolean ignoreCase, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes, Evidence securityInfo, StackCrawlMark& stackMark) 
at System.Activator.CreateInstance(String assemblyName, String typeName) 
at System.AppDomain.CreateInstance(String assemblyName, String typeName) 
at System.AppDomain.InternalCreateInstanceWithNoSecurity(String assemblyName, String typeName) 
at System.AppDomain.InternalCreateInstanceWithNoSecurity(String assemblyName, String typeName) 
at System.Activator.CreateInstance(AppDomain domain, String assemblyName, String typeName) 
at System.Web.Hosting.ApplicationManager.CreateAppDomainWithHostingEnvironment(String appId, IApplicationHost appHost, HostingEnvironmentParameters hostingParameters) 
at System.Web.Hosting.ApplicationManager.CreateAppDomainWithHostingEnvironmentAndReportErrors(String appId, IApplicationHost appHost, HostingEnvironmentParameters hostingParameters)

該應用程序將繼續在IIS中運行。這個IIS也承載了一大堆其他網站沒有任何問題。是的，該應用程序設置爲在.NET 4上運行，而服務器託管其他.NET 4應用程序也沒有任何問題。

從我可以告訴，它不能加載System.Web程序集，但我不知道怎麼說甚至有可能...

下面是應用程序的Web.config：

<?xml version="1.0"?> 
<configuration> 
    <system.web> 
     <globalization culture="nb-NO"/> 
     <compilation debug="true" targetFramework="4.0"> 
      <assemblies> 
       <add assembly="System.Data.Linq, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/> 
      </assemblies> 
      </compilation> 
     <customErrors mode="Off"></customErrors> 
     <xhtmlConformance mode="Strict"/> 
     <httpRuntime requestValidationMode="2.0"/> 
    </system.web> 
    <system.webServer> 
     <modules runAllManagedModulesForAllRequests="true"></modules> 
    </system.webServer> 
</configuration>

來源

2011-05-24 Stian Hanger