I have deployed a Episerver R1 version 5 site on a Windows Server 2008 (IIS 7,0), but get this error when I try to open the site in the browser:

 Object reference not set to an instance of an object.
Description: An unhandled exception occurred during the execution of the current web  request. Please review the stack trace for more information about the error and where it  originated in the code.

Exception Details: System.NullReferenceException: Object reference not set to an  instance of an object.

Source Error:

[No relevant source lines]


Source File: c:\Windows\Microsoft.NET\Framework64\v2.0.50727\Temporary ASP.NET  Files\root\5916dba4\848ed34d\App_global.asax.uoixjynr.0.cs    Line: 0

Stack Trace:

[NullReferenceException: Object reference not set to an instance of an object.]
   System.Web.Security.UrlAuthorizationModule.CheckUrlAccessForPrincipal(String  virtualPath, IPrincipal user, String verb) +1007
   EPiServer.Web.Hosting.VirtualPathNativeProvider.QueryAccess(String virtualPath,  IPrincipal user) +93
   EPiServer.Web.Hosting.UnifiedDirectory.QueryDistinctAccess(AccessLevel access)  +25
   EPiServer.Web.Hosting.VirtualPathNativeProvider.GetDirectory(String virtualPath) +192
  EPiServer.Web.Hosting.VirtualPathHandler.InitializeProviders(ProviderSettingsCollection  providers) +465
   EPiServer.Global.InitializeVirtualPathProviders() +83
   EPiServer.Global..ctor() +529
   Esthetique.Intranett.Web.Global..ctor() +47
   ASP.global_asax..ctor() in  c:\Windows\Microsoft.NET\Framework64\v2.0.50727\Temporary ASP.NET  Files\root\5916dba4\848ed34d\App_global.asax.uoixjynr.0.cs:0

The same files is working on XP and ISS 6.0. Hope somebody have some suggestion on how to come around this problem.