调用UserPrincipal.FindByIdentity时出现DirectoryServiceCOMExceptio

试图解决基于AD凭据创建用户的错误，我得到了上述异常，但由于访问限制，我的可用信息在某种程度上仅限于日志文件。我知道这是一个权限问题，但我发现的所有建议都没有产生不同的结果。

这个主要项目被设置为使用表单身份验证和匿名身份验证，但我们有一个单独的"员工"项目，使用Windows身份验证来针对AD对内部用户进行身份验证。

根据我发现的建议，我更改了以下内容：

• 在AppPool上将.Net Framework更改为4.x
• 尝试通过IIS接口启用.Net模拟
• 已更改匿名身份验证以使用应用程序池标识
• Identity设置为ApplicationPoolIdentity-更改为网络会导致应用程序池停止

当前服务器配置正在使用同一AD服务器的内部暂存服务器上运行。这是我在日志中得到的堆栈转储：

2014-09-09 15:33:24,365 |28| (Services.Security.UserManagement.UserPrincipal) [ INFO] - About to call FindByIdentity 
2014-09-09 15:33:24,365 |28| (Services.Security.UserManagement.UserPrincipal) [ INFO] - Current IIS user is: IIS APPPOOL'DefaultAppPool 
2014-09-09 15:33:24,397 |28| (Services.Security.UserManagement.UserPrincipal) [ERROR] - EXCEPTION in Method: Initialize - Exception: System.DirectoryServices.DirectoryServicesCOMException (0x80072020): An operations error occurred.
   at System.DirectoryServices.DirectoryEntry.Bind(Boolean throwIfFail)
   at System.DirectoryServices.DirectoryEntry.Bind()
   at System.DirectoryServices.DirectoryEntry.get_AdsObject()
   at System.DirectoryServices.PropertyValueCollection.PopulateList()
   at System.DirectoryServices.PropertyValueCollection..ctor(DirectoryEntry entry, String propertyName)
   at System.DirectoryServices.PropertyCollection.get_Item(String propertyName)
   at System.DirectoryServices.AccountManagement.PrincipalContext.DoLDAPDirectoryInitNoContainer()
   at System.DirectoryServices.AccountManagement.PrincipalContext.DoDomainInit()
   at System.DirectoryServices.AccountManagement.PrincipalContext.Initialize()
   at System.DirectoryServices.AccountManagement.PrincipalContext.get_QueryCtx()
   at System.DirectoryServices.AccountManagement.Principal.FindByIdentityWithTypeHelper(PrincipalContext context, Type principalType, Nullable`1 identityType, String identityValue, DateTime refDate)
   at System.DirectoryServices.AccountManagement.UserPrincipal.FindByIdentity(PrincipalContext context, String identityValue)
   at Services.Security.UserManagement.UserPrincipal.Initialize() 
System.DirectoryServices.DirectoryServicesCOMException (0x80072020): An operations error occurred.

导致异常的代码如下：

private void Initialize()
{
    if (this.principal == null)
    {
        if (HttpContext.Current != null)
        {
            HttpCookie cookie = HttpContext.Current.Request.Cookies[ConstantsEnum.WindowsAuthCookie];
            if (cookie != null)
            {
            string username = this.AesEncryptor.Decrypt(cookie.Value);
                this.context = new PrincipalContext(ContextType.Domain, ConstantsEnum.DomainName);
                this.principal = System.DirectoryServices.AccountManagement.UserPrincipal.FindByIdentity(this.context, username);
                if (this.principal == null)
                {
                        throw new ArgumentNullException(string.Format("The UserPrincipal for {0} was not found.", username));
                }
            }
        }
    }