title: Exchange 2013 issues after CU9
body: <p>I have a MS Exchange 2013 server that worked fine until I installed CU9 KB3087126.</p>
  
  <p><strong>Issues:</strong></p>
  
  <p>ECP is not accesible from the outside.</p>
  
  <p>ECP is accessible from the inside using "<a href="https://server_name/ecp" rel="nofollow">https://server_name/ecp</a>" but after entering the credentials I get a page with "Server Error in '/ecp' Application."</p>
  
  <pre><code>Could not load file or assembly 'Microsoft.Exchange.Common, Version=15.0.0.0, Culture=neutral, PublicKeyToken=token_here' or one of its dependencies. The system cannot find the file specified. 
    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.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.Exchange.Common, Version=15.0.0.0, Culture=neutral, PublicKeyToken=token_here' or one of its dependencies. The system cannot find the file specified.
  
  Source Error: 
  An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.  
  
  Assembly Load Trace: The following information can be helpful to determine why the assembly 'Microsoft.Exchange.Common, Version=15.0.0.0, Culture=neutral, PublicKeyToken=token_here' could not be loaded.
  
  WRN: Assembly binding logging is turned OFF.
  To enable assembly bind failure logging, set the registry value [HKLM\Software\Microsoft\Fusion!EnableLog] (DWORD) to 1.
  Note: There is some performance penalty associated with assembly bind failure logging.
  To turn this feature off, remove the registry value [HKLM\Software\Microsoft\Fusion!EnableLog].
  
  Stack Trace: 
  
  [FileNotFoundException: Could not load file or assembly 'Microsoft.Exchange.Common, Version=15.0.0.0, Culture=neutral, PublicKeyToken=token_here' or one of its dependencies. The system cannot find the file specified.]
     System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMarkHandle stackMark, IntPtr pPrivHostBinder, Boolean loadTypeFromPartialName, ObjectHandleOnStack type) +0
     System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark&amp; stackMark, IntPtr pPrivHostBinder, Boolean loadTypeFromPartialName) +153
     System.Type.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase) +63
     System.Web.Compilation.BuildManager.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase) +124
     System.Web.Configuration.ConfigUtil.GetType(String typeName, String propertyName, ConfigurationElement configElement, XmlNode node, Boolean checkAptcaBit, Boolean ignoreCase) +76
  
  &gt;[ConfigurationErrorsException: Could not load file or assembly 'Microsoft.Exchange.Common, Version=15.0.0.0, Culture=neutral, PublicKeyToken=token_here' or one of its dependencies. The system cannot find the file specified.]
     System.Web.Configuration.ConfigUtil.GetType(String typeName, String propertyName, ConfigurationElement configElement, XmlNode node, Boolean checkAptcaBit, Boolean ignoreCase) +12425660
     System.Web.Configuration.Common.ModulesEntry.SecureGetType(String typeName, String propertyName, ConfigurationElement configElement) +69
     System.Web.Configuration.Common.ModulesEntry..ctor(String name, String typeName, String propertyName, ConfigurationElement configElement) +62
     System.Web.HttpApplication.BuildIntegratedModuleCollection(List`1 moduleList) +299
     System.Web.HttpApplication.GetModuleCollection(IntPtr appContext) +1262
     System.Web.HttpApplication.RegisterEventSubscriptionsWithIIS(IntPtr appContext, HttpContext context, MethodInfo[] handlers) +133
     System.Web.HttpApplication.InitSpecial(HttpApplicationState state, MethodInfo[] handlers, IntPtr appContext, HttpContext context) +304
     System.Web.HttpApplicationFactory.GetSpecialApplicationInstance(IntPtr appContext, HttpContext context) +404
     System.Web.Hosting.PipelineRuntime.InitializeApplication(IntPtr appContext) +475
  
  [HttpException (0x80004005): Could not load file or assembly 'Microsoft.Exchange.Common, Version=15.0.0.0, Culture=neutral, PublicKeyToken=token_here' or one of its dependencies. The system cannot find the file specified.]
     System.Web.HttpRuntime.FirstRequestInit(HttpContext context) +12618996
     System.Web.HttpRuntime.EnsureFirstRequestInit(HttpContext context) +159
     System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +12458613
  </code></pre>
  
  <p>In the Event log I have a WARNING from ASP.NET 4.0.30319.0 with EventID 1310 saying:</p>
  
  <pre><code>Event code: 3008 
  Event message: A configuration error has occurred. 
  Event time: 7/20/2016 2:34:28 PM 
  Event time (UTC): 7/20/2016 11:34:28 AM 
  Event ID: a59d5b2b449a4b968766e110bc5704a6 
  Event sequence: 1 
  Event occurrence: 1 
  Event detail code: 0 
  
  Application information: 
      Application domain: /LM/W3SVC/2/ROOT/ecp-12-131134880684035632 
      Trust level: Full 
      Application Virtual Path: /ecp 
      Application Path: C:\Program Files\Microsoft\Exchange Server\V15\ClientAccess\ecp\ 
      Machine name: name_here 
  
  Process information: 
      Process ID: 11208 
      Process name: w3wp.exe 
      Account name: NT AUTHORITY\SYSTEM 
  
  Exception information: 
      Exception type: ConfigurationErrorsException 
      Exception message: Could not load file or assembly 'Microsoft.Exchange.Common, Version=15.0.0.0, Culture=neutral, PublicKeyToken=token_here' or one of its dependencies. The system cannot find the file specified.
     at System.Web.Configuration.ConfigUtil.GetType(String typeName, String propertyName, ConfigurationElement configElement, XmlNode node, Boolean checkAptcaBit, Boolean ignoreCase)
     at System.Web.Configuration.Common.ModulesEntry.SecureGetType(String typeName, String propertyName, ConfigurationElement configElement)
     at System.Web.Configuration.Common.ModulesEntry..ctor(String name, String typeName, String propertyName, ConfigurationElement configElement)
     at System.Web.HttpApplication.BuildIntegratedModuleCollection(List`1 moduleList)
     at System.Web.HttpApplication.GetModuleCollection(IntPtr appContext)
     at System.Web.HttpApplication.RegisterEventSubscriptionsWithIIS(IntPtr appContext, HttpContext context, MethodInfo[] handlers)
     at System.Web.HttpApplication.InitSpecial(HttpApplicationState state, MethodInfo[] handlers, IntPtr appContext, HttpContext context)
     at System.Web.HttpApplicationFactory.GetSpecialApplicationInstance(IntPtr appContext, HttpContext context)
     at System.Web.Hosting.PipelineRuntime.InitializeApplication(IntPtr appContext)
  
  &gt;Could not load file or assembly 'Microsoft.Exchange.Common, Version=15.0.0.0, Culture=neutral, PublicKeyToken=token_here' or one of its dependencies. The system cannot find the file specified.
     at System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMarkHandle stackMark, IntPtr pPrivHostBinder, Boolean loadTypeFromPartialName, ObjectHandleOnStack type)
     at System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark&amp; stackMark, IntPtr pPrivHostBinder, Boolean loadTypeFromPartialName)
     at System.Type.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase)
     at System.Web.Compilation.BuildManager.GetType(String typeName, Boolean throwOnError, Boolean ignoreCase)
     at System.Web.Configuration.ConfigUtil.GetType(String typeName, String propertyName, ConfigurationElement configElement, XmlNode node, Boolean checkAptcaBit, Boolean ignoreCase)
  
  
  
  Request information: 
      Request URL: https://localhost:444/ecp/exhealth.check 
      Request path: /ecp/exhealth.check 
      User host address: ::1 
      User:  
      Is authenticated: False 
      Authentication Type:  
      Thread account name: NT AUTHORITY\SYSTEM 
  
  Thread information: 
      Thread ID: 35 
      Thread account name: NT AUTHORITY\SYSTEM 
      Is impersonating: False 
      Stack trace:    at System.Web.Configuration.ConfigUtil.GetType(String typeName, String propertyName, ConfigurationElement configElement, XmlNode node, Boolean checkAptcaBit, Boolean ignoreCase)
     at System.Web.Configuration.Common.ModulesEntry.SecureGetType(String typeName, String propertyName, ConfigurationElement configElement)
     at System.Web.Configuration.Common.ModulesEntry..ctor(String name, String typeName, String propertyName, ConfigurationElement configElement)
     at System.Web.HttpApplication.BuildIntegratedModuleCollection(List`1 moduleList)
     at System.Web.HttpApplication.GetModuleCollection(IntPtr appContext)
     at System.Web.HttpApplication.RegisterEventSubscriptionsWithIIS(IntPtr appContext, HttpContext context, MethodInfo[] handlers)
     at System.Web.HttpApplication.InitSpecial(HttpApplicationState state, MethodInfo[] handlers, IntPtr appContext, HttpContext context)
     at System.Web.HttpApplicationFactory.GetSpecialApplicationInstance(IntPtr appContext, HttpContext context)
     at System.Web.Hosting.PipelineRuntime.InitializeApplication(IntPtr appContext)
  </code></pre>
  
  <p>In the Queue Viewer I have a lot of emails headed towards certain domains that are stuck with the error:</p>
  
  <pre><code>[{LRT=7/20/2016 2:40:17 PM};{LED=450 4.7.0 Proxy session setup failed on Frontend with '451 4.4.0 DNS query failed. The error was: DNS query failed with error ServerFailure'};{FQDN=correct_fqdn_here};{IP=correct_ip}]
  </code></pre>
  
  <p><strong>What works:</strong></p>
  
  <p>OWA works from the inside and outside;</p>
  
  <p>Apart from some emails to specific domains (small companies) inbound/outbound emails work from inside and outside of the company.(Tested with a Gmail account, testconnectivity.microsoft.com and received confirmation that emails from some big companies are being received - ex. hp.com)</p>
  
  <p>Apart from the CU9 Update, nothing was changed prior to the update.</p>
  
  <p>Searched the web a lot before asking but nothing helped. I'm guessing most of the issues are because ECP is not working. </p>
  
  <p>Has anyone encountered this issue before and has an idea how to fix it?</p>
  
  <p>Thanks in advance!</p>