Troubleshooting tips for Exchange 2013 OWA IM Integration to Lync 2013

This post describes how to configure Exchange 2013 OWA to have IM integration to Lync 2013. Here I would like to give some troubleshooting tips in case you can't get the integration to work.

Web.Config edits

  • Make sure you edit the OWA web.config file on the MBX server(s)
  • Make sure it has the right format, i.e. no space after the hex characters in the certificate thumbprint and ending /> brackets
    • <add key="IMCertificateThumbprint" value="EA5A332496CC05DA69B75B66111C0F78A110D22" />
    • <add key="IMServerName" value="" />
  • Make sure you add the two lines in the right section of the OWA web.config file (<appSettings>)
  • Make sure to restart the MSExchangeOWAAppPool after the edit


  • Make sure that the certificate you use on the MBX server is trusted by the Lync 2013 server and vice versa. Typically this means using certificates from a mutually trusted CA, perhaps the enterprise CA
  • Make sure the subject name of the certificate and one of the subject alternative names¬†are the FQDN of the MBX server

OwaVirtualDirectory and OwaMailboxPolicy

  • Make sure you have set InstantMessagingEnabled to $true and set InstantMessagingType to Ocs


  • Make sure the user has a proxy address with SIP type (you can set it in EMS with the cmdlet set-Mailbox¬†<alias> -EmailAddresses @{Add="SIP:<SIP URI, i.e.>"})
  • Make sure that the CASMailbox representing the user has the appropriate OwaMailboxPolicy

Signing in

  • Look for event ID 112 from MSExchange OWA on the MBX server signaling that the Instant Messaging Endpoint Manager was initialized successfully. This happens at first IM sign-in after OWA App Pool restart
  • If you get event 112, but the user is still not able to sign in, check certificates and that the user has the SIP proxy address

Lync 2013 Topology

  • If the Exchange 2013 MBX server is also hosting a UM dial plan of URITYpe SipName do not add the Exchange 2013 MBX server as a Trusted Application Pool. The Exchange UM integration in Lync 2013 will automatically add the Exchange 2013 MBX server as a trusted server in Lync 2013

Logfile and tracing

  • OWA IM Integration writes logfiles to the directory C:\Program Files\Microsoft\Exchange Server\V15\Logging\OWA\InstantMessaging on the MBX server. If there is no logfile in that directory or no InstantMessaging directory, OWA itself has not yet understood that it needs to support IM integration to Lync
  • On the Lync 2013 server use SIPStack tracing (All Levels and All Flags) to get an idea of what might be wrong (Use LyncDebugTools.msi
  • On Exchange 2013 MBX you can use OcsTracer.exe in C:\Program Files\Microsoft UCMA 4.0\Runtime\Tracing to see the SIP traffic generated by OWA IM
    • To Start: OCSTracer.exe Start /Component:Collaboration,TL_noise,tf_component,tf_diag,tf_protocol,tf_connection /Component:S4,TL_VERBOSE,tf_component,tf_protocol /LogFileMode:NewFile,20
    • To Stop and see traces: OCSTracer Stop /Component:Collaboration /component:s4 /OutputFile:traces.txt /View