Exchange 2007 Active sync error An HTTP 500 response was returned from Unknown.

Question

I tested using Microsoft Remote connectivity analyzer tool and getting following error. Please help me to fix the issue
An ActiveSync session is being attempted with the server.
Errors were encountered while testing the Exchange ActiveSync session.
Additional Details
Elapsed Time: 394 ms.
Test Steps
Attempting to send the OPTIONS command to the server.
Testing of the OPTIONS command failed. For more information, see Additional Details.
Additional Details
An HTTP 500 response was returned from Unknown. Headers received: Content-Length: 3745 Cache-Control: private Content-Type: text/html; charset=utf-8 Date: Wed, 05 Mar 2014 18:09:36 GMT Server: Microsoft-IIS/6.0 X-AspNet-Version: 2.0.50727 X-Powered-By:
ASP.NET HTTP Response Headers: Content-Length: 3745 Cache-Control: private Content-Type: text/html; charset=utf-8 Date: Wed, 05 Mar 2014 18:09:36 GMT Server: Microsoft-IIS/6.0 X-AspNet-Version: 2.0.50727 X-Powered-By: ASP.NET
Elapsed Time: 394 ms.

Answer 1

Hi Shadab,
I have recreated the active sync virtual directory but didnt fix the issue. I have set the logging level for active sync to high and getting below event logs in apps log
Event Type: Warning
Event Source: ASP.NET 2.0.50727.0
Event Category: Web Event 
Event ID: 1310
Date: 08/03/2014
Time: 17:50:29
User: N/A
Computer: HP-01
Description:
Event code: 3008 
Event message: A configuration error has occurred. 
Event time: 08/03/2014 17:50:29 
Event time (UTC): 08/03/2014 17:50:29 
Event ID: 5ff3055057084fb49978442a86866e50 
Event sequence: 15 
Event occurrence: 14 
Event detail code: 0 
Application information: 
    Application domain: /LM/W3SVC/1/ROOT/Microsoft-Server-ActiveSync-1-130384798306406250 
    Trust level: Full 
    Application Virtual Path: /Microsoft-Server-ActiveSync 
    Application Path: C:\Program Files\Microsoft\Exchange Server\ClientAccess\sync\ 
    Machine name: HP-01 
Process information: 
    Process ID: 1972 
    Process name: w3wp.exe 
    Account name: NT AUTHORITY\SYSTEM 
Exception information: 
    Exception type: ConfigurationErrorsException 
    Exception message: Could not load file or assembly 'Microsoft.Exchange.Clients.Owa' or one of its dependencies. The system cannot find the file specified. (C:\Program Files\Microsoft\Exchange Server\ClientAccess\Owa\web.config line 64) (C:\Program
Files\Microsoft\Exchange Server\ClientAccess\Owa\web.config line 64) 
Request information: 
    Request URL: https://mail.itech-it.co.uk:443/Microsoft-Server-ActiveSync/default.eas 
    Request path: /Microsoft-Server-ActiveSync/default.eas 
    User host address: 157.56.138.141 
    User:  
    Is authenticated: False 
    Authentication Type:  
    Thread account name: NT AUTHORITY\SYSTEM 
Thread information: 
    Thread ID: 8 
    Thread account name: NT AUTHORITY\SYSTEM 
    Is impersonating: False 
    Stack trace:    at System.Web.Configuration.HttpModuleAction.get_Entry()
   at System.Web.Configuration.HttpModulesSection.CreateModules()
   at System.Web.HttpApplication.InitInternal(HttpContext context, HttpApplicationState state, MethodInfo[] handlers)
   at System.Web.HttpApplicationFactory.GetNormalApplicationInstance(HttpContext context)
   at System.Web.HttpApplicationFactory.GetApplicationInstance(HttpContext context)
   at System.Web.HttpRuntime.ProcessRequestInternal(HttpWorkerRequest wr)
Custom event details: 
For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
Thanks!
Rajeesh