Troubleshooting Microsoft Office Communicator Issues 101

Much has been written about troubleshooting Microsoft Office Communicator issues. In this blog entry I wanted to highlight and simplify two steps that will help you catch most problems without having to do more time consuming troubleshooting.

1) Know Which DNS Records are Being Used by Communicator

Communicator relies heavily on DNS to figure out which OCS server to connect to.  Knowing how Communicator uses DNS, and what DNS records are being returned with the client DNS settings, is the key to debugging most issues.

My previous post, DNS Records and Office Communicator Automatic Client Sign-In, summarizes how Communicator uses DNS to connect to the server.

My Automatic Sign-In Troubleshooting Tool will query the local client DNS for all the DNS records Communicator might use, and display which ones match.

Knowing what DNS records are being used and which server Communicator is connecting to will help you understand the logging files in the next step.

2) Turn on and Use Communicator Logging

a) Turn on Communicator Event Logging (Options | General | Turn on Windows Event logging for Communicator)

This will produce explicit Application event log entries for any issues Communicator is experiencing.  For example: “Communicator could not connect securely to server because the certificate presented by the server did not match the expected hostname (”.  There may be additional Informational or Warning log entries that provide additional context.

b) Turn on regular Communicator Logging (Options | General | Turn on logging in Communicator)

This generates a debugging log file in %userprofile%/Tracing (e.g. the filename will look something like “Communicator-uccapi-0.iccapilog”).  This log file will give specific details about what Communicator is doing internally. For example, we can clearly see in this log file there is a DNS hostname lookup failure:

  • 06/05/2009|10:26:45.553 700:EE8 INFO  :: QueryDNSSrv – DNS Name[]
  • 06/05/2009|10:26:45.563 700:FAC INFO  :: serviceName:sip: transportName:tls:
  • 06/05/2009|10:26:45.563 700:EE8 ERROR :: QueryDNSSrv GetDnsResults query: failed 9
  • 06/05/2009|10:26:45.563 700:EE8 ERROR :: DNS_RESOLUTION_WORKITEM::ProcessWorkItem ResolveHostName failed 8007232b

(Note this file can be opened in Notepad even though it does not have a .txt file extension).

Taking these first steps will go a long way in understanding how Communicator is behaving.

The Microsoft TechNet Library has a more good information on troubleshooting specific Communicator R2 Features:

Finally, if you are troubleshooting an issue with Communicator R2, take advantage of the built-in diagnostic information. See the previous post regarding the ”Great New Office Communicator R2 Troubleshooting Feature” for more information.

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13 comments to Troubleshooting Microsoft Office Communicator Issues 101

  • Dora

    Communicator loging on/off automatically every few seconds non-stop. I noticed the problem occurred after I did remote desktop connection to several virtual machines I was testing login (needed to know if they were active in the network). Ever since, this problem is occurring and my support group cannot find the issue.

  • Hi Mike, glad to hear you fixed it. I am surprised removing the users profile fixed this – did you find this solution somewhere? i.e. is it a well known issue?

    I have seen this problem before (minus the expired error message) when Kaspersky antivirus installed on the recipient’s computer. BTW, you should always get logging on both clients (assuming it is enabled).


  • Mike D

    Removing the Communicator directories within the user’s profile fixed mine.
    %userprofile%/Appdata/local/Microsoft and %userprofile%/Appdata/Roaming/Microsoft remove Communicator from both.

  • Mike D

    When I send a request to share my Desktop the other user never receives the notification but the Communicator window is frozen. after the session times out she receives the following message “The request to join the sharing session that was sent to USERNAME has expired.”

    I have tried to turn on logging on both ends.nothing is ever populated in the files. Also Windows logging does not generate an error.


  • Hi Michael,

    I have seen this problem *once* before about 2 years ago – I am struggling to remember the fix but it was something simple on the display (your display properties) in this case.

    I am pretty sure the user who was experiencing the problem had changed the size of her text in the Windows display properties from “Smaller” (100%) to “Medium” (125%). Once we set it back the problem went away. It was either that or the display resolution.

    I don’t know if this is your issue, but you may want to give that a whirl.

    Hope that helps, Curtis

  • Michael Fox

    When I try to Screen Share using Communicator (v. 3.5*) the other party just sees mostly a black screen, with a few horizontal lines of my screen showing through. I can view someone else who Screen Shares with me. I checked with someone using the same computer, same display properties as I have and I can see their screen, they cannot see mine.

    Any suggestions would be much appreciated!

  • Rosemary DeLorey

    We’re experencing an issue with OC automatically placing calls (incoming or outgoing) on hold. It’s not all the time, it seems to resolve itself for a period of time, then it rears it’s ugly head again and people start complaining about this issue. We run an Avaya phone system. After researching on line and reading what others have experienced and have to say, unintegrating OC seems to have the best result of this to stop happening but it sort of defeats the purpose for having it and having it fully integrated with phones.
    Much reading and much thought has gone into these complaints. I’m wondering if you might have a solution for this issue and I know there are many others out there experiencing the very same problem

  • Philip, one more idea – in the external clients you can hardcode the FQDN hostname of your Lync or OCS Edge server (in Options, Advanced Sign-In) and attempt to sign-in.

    This will tell you if it is DNS issues or some other issue.


  • Philip, there could be many reasons besides DNS that external users cannot sign-in.

    From the information you provided, if you would like external users to sign in automatically using the SIP domain, you will need one of these domains resolvable to the access Edge externally in DNS: or Neither of those records are returning a match in DNS based on the results you provided.

    I noticed the domain your using in my tool is actually “”. If that is the external SIP domain you want to support you will need to use that domain instead (i.e. or

    Hope that helps,

  • Philip

    Please advise, we have 2 SIP domains

    ABC.local (ad default)

    Please see my results below & advise, what must I do to correct my scenario. All the internal users can sign-in. External users cannot.

    OCS DNS Records Found

    OCS DNS Records Not Found
    _sipinternaltls._tcp.pgclync.ABC.local *** Request to UnKnown timed-out

    _sipinternal._tcp.pgclync.ABC.local *** Request to UnKnown timed-out

    _sip._tls.pgclync.ABC.local *** Request to UnKnown timed-out

    _sip._tcp.pgclync.ABC.local *** Request to UnKnown timed-out

    sipinternal.pgclync.ABC.local *** Request to UnKnown timed-out

    sip.pgclync.ABC.local *** Request to UnKnown timed-out

    sipexternal.pgclync.ABC.local *** Request to UnKnown timed-out

    OCS DNS Records Found

    OCS DNS Records Not Found *** UnKnown can’t find Non-existent domain *** UnKnown can’t find Non-existent domain *** UnKnown can’t find Non-existent domain *** UnKnown can’t find Non-existent domain *** UnKnown can’t find Non-existent domain *** UnKnown can’t find Non-existent domain *** UnKnown can’t find Non-existent domain

  • Shakti Moudgil

    Hi Curtis,

    There is a user in our company server team give him Audio Video access on OCS, but while using his system user unable to use these features, then i recreate user profile on same system it not works. So i check on local admin on same system using his id it works. So, we check on other system using his id this feature works on his id. So will you suggest me what’s the issue with his profile and need your suggestion on this. Please mail me on

    Shakti Moudgil

  • Without knowing anything about your situation or environment (e.g. just external contacts or all contacts?, OCS 2007 R2 or Lync on the server side?, was it working at one time and the presence unknown just started?) it is hard to recommend anything.

    I can tell you that there were hotfixes released quite some time ago (+1 years) on both the client and server side that have fixed this problem.

    Making sure your Communicator 2007 R2 Clients and OCS/Lync Servers are completely up-to-date is a great first step.


  • Vineet

    Contacts in Microsoft office communicator 2007 R2 are showing presence unknown. please suggest

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