XML Error After Login

I am trying to setup filevista 3.5 on a Windows 2008 32 bit server.  
I am using defaultapp pool ASP .net 4.0, integrated with network service identity.

The application loads but after I enter login info, I get an XML error. In the event log I see this:

Exception information: 
    Exception type: NullReferenceException 
    Exception message: Object reference not set to an instance of an object.
   at GleamTech.FileVista.AuthenticationManager.Authenticate(HttpContext context) in O:\GI FTP\webftpx86\AuthenticationManager.cs:line 23
   at GleamTech.FileVista.FileVistaGlobalAsax.Application_AcquireRequestState(Object sender, EventArgs e) in O:\GI FTP\webftpx86\Global.asax.cs:line 66
   at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

 
 
Request information: 
    Request URL: http://localhost/webftp/administration.asmx/LoginUser 
    Request path: /webftp/administration.asmx/LoginUser 
    User host address: ::1 
    User:  
    Is authenticated: False 
    Authentication Type:  
    Thread account name: NT AUTHORITY\NETWORK SERVICE 
 
Thread information: 
    Thread ID: 8 
    Thread account name: NT AUTHORITY\NETWORK SERVICE 
    Is impersonating: False 
    Stack trace:    at GleamTech.FileVista.AuthenticationManager.Authenticate(HttpContext context) in O:\GI FTP\webftpx86\AuthenticationManager.cs:line 23
   at GleamTech.FileVista.FileVistaGlobalAsax.Application_AcquireRequestState(Object sender, EventArgs e) in O:\GI FTP\webftpx86\Global.asax.cs:line 66
   at System.Web.HttpApplication.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
 

The error occurs because the session state is not available for the application.

First make sure that this line is included in application's web.config:

<sessionState mode="InProc"/>

Then make sure that the following line is included in your machine's global web.config (C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\CONFIG\web.config) under <httpModules> section:

<add name="Session" type="System.Web.SessionState.SessionStateModule"/>

Or you can try to include the above line in the application's web.config instead.