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Users are unable to login

  • I have installed several users with the Lync 2010 client and some users are unable to connect to the Lync server. After install Lync opens and when I type in the users email address I get an error message back that the Lync server is temporarily down. The client has been installed on 12 employees PC's. 3 of the 12 are experiencing this issue. I have checked their Lync settings on the Office365 Admin portal and all users are enabled for Lync. I've also set their client to manually connect to Lync by adding but that did not work either.


    Thank you,


  • Have you run the "Configure Your Desktop Apps" for each of these clients as described here:

  • Hi Joe,

    Based on current situation, please try the following action plan to resolve the problem.

    1. If you didn't run office 365 desktop set up on the problematic computers then please run it first.

    2. Double confirmed you configure the problematic Lync clients use manually Lync settings
    a. In the upper-right area of Lync 2010, click the Gear icon to open the Options page.
    b. In the Lync - Options dialog box, click Personal.
    c. Next to the sign-in address, click Advanced.
    d. Make sure that Manual Configuration is selected and that the configuration values are exactly as follows:
        Internal server name or IP address:
        External server name or IP address:
    e. Try to sign in Lync again.

    If the action plan didn't work, then please help narrow down the issue.

    1. Did the problematic users can login Lync on other computers?

    2. Is there any different between the problematic computers and the worked computers?

    Best regards,
    Alex Du

  • Hi Joe,

    Did the issue fix? If not, please help narrow down the issue. Thanks.

    Alex Du

  • The issue has not been resolved. The user is able to use a different PC and log in. My account works fine, but I cannot log in on the computer that is having the issue so I do not believe it is user realted. I uninstalled Lync, re-installed, installed the desktop app sign in, tried putting in

    into the Lync client (btw, I get an immediate response back that the server is unavailable when I do that) and nothing seems to work. I was able to use the cmd prompt to do nslookup on an the addresses and I got a valid response back on all lookup. So am not sure where the problem is.

  • Hi Joe,

    I agree with you it’s not user related issue (User relevant configurations should be correct). The issue should relate to the computer configurations due to you the account can login on another computer. Usually there were many factors may cause such issue. For example: Firewall configurations; software conflicts, etc. (in some special cases, the issue was related to local user profiles.)

    • I understand you test the server with nslookup. However, it doesn’t mean the Lync connections will not be blocked.

    Based on current situation, please follow the action plans below to fix the issue.

    1. Disable firewall on the computer and retry or you can follow the article below to configure the computer’s firewall.

    You cannot connect to Lync Online, or certain features do not work, because an on-premises firewall blocks the connection

    2. Reboot the computer to clean boot mode and to see if the issue fixed under clean boot mode.
    How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7

    3. Uninstall Lync online and then reinstall it and desktop app again.

    4. Create a new local user and login with the new user. (In rare case, some customer fix the similar issue by refresh install)

    Best regards,
    Alex Du

  • Hi Joe,

    Did the issue fix? If you need further assistance, please let me know. Thanks.

    Alex Du

  • The issue is still unresolved. I disabled the firewall AND anti-virus software and am still unable to log on to Lync. I uninsalled the software, rebooted and re-installed but I still cannot log in. I think at one point I logged onto the user machine and was able to log in to Lync and they were able to log in as well. I have to verify this again as I can't remember exactly what I did. Have there been issue with Lync and users profiles on the machine using Windows 7?

  • Hi Joe,

    The issue may be caused by several factors. The user profile is one of the factors. So please create a new user and retry to help narrow down the issue. Thanks.

    Alex Du

  • I was able to log on locally to the pc and log into Lync with my user name and the user of the pc's user name. I was also able to log onto the pc with an account that had not logged on to the pc before and I was able to log onto Lync. I removed the users profile (which is really not something we want to do as we will have to remap printers, shared drives, Outlook, favorites etc) and logged back onto the PC and was NOT able to log onto Lync. So the issue is definetly user profile based. Is there a way to fix the profile without having to remove the users profile, uninstalling Lync, reinistalling Lync and recreating the user profile? I don't think doing all that is an option for us when the install is failing on 25% of our users PC's.

  • Same issue here we have roaming profiles with xenapp and in some servers works and in another doesn't work we delete the roaming profile but it still fails when we log in again in that server, we have deleted al related registry keys but still doesn't work.

    we have been upgraded to office 365 recently and no one can use lync inside xenapp because this issue.

  • Hello Joe,

    If the users are able to sign in from other computers, this means there is nothing wrong with their computer.  If you are getting a message that the sever temporarily unavailable, this suggests the Lync Client is unable to locate the server.   If you’re manually configuring the Lync Client, and immediately receive a response that the server is unavailable, you may have cached DNS information which is not valid.  Please attempt to flush the DNS cache with the following command:  ipconfig /flushdns

    If flushing the DNS resolver cache does not resolve the problem, you should do a clean install of the Lync Client including deleting stored certificates and deleting the end-point cache.  See the instructions blow.

    1. Go to Add/Remove Programs in the Control Panel.

    2. Remove the Lync Client and the Microsoft Online Services Sign-in Assistant.

    3. Click Start.

    4. In the Search box, type: certmgr.msc

    5. Expand the Personal folder, then the Certificates folder.

    6. Delete any certificates issued by Communications Server.

    7. Delete the contents of the following folder: C:\Users\USERNAME\Tracing

    8. Delete the following folder: C:\Users\USERNAME\AppData\Local\Microsoft\Communicator\USERNAME

    9. Log-in to the administrator portal at:

    10. Download the Lync Client. The download link is on the right hand side of the page.

    11. Install the Lync client.  Do not run the Lync client when the installation completes.

    12. Run the Set up and configure your Office desktop apps utility.

    13. Open the Lync client.

    14. Click the Gear drop-down and choose Tools -> Options.

    15. Click General in the left pane.

    16. Under logging, place a check mark next to both options: Turn on logging in Lync, and Turn on Windows Event Logging for Lync.

    17. Attempt to sign-in to Lync.

    Thank you for contacting Microsoft Lync Online Support,

    Donovan Venuto

    1-800-865-9408 (24 hour support)

    Microsoft Lync Online Support

    Technical Support Representative

  • This did not work. I tried it on 3 of users that are having issues and I get the same problem. I believe it to be profile based. I think removing the profile then adding back may work, but unfortunately, that is not an option for me. That would mean recreating all their shares, printer mappings, favorites, desktop, Outlook, etc. I should not have to remove a profile to get this to work.

  • Hello Joe,

    Have you made any progress on this issue?  If you believe the problem is related to the profile, have you tried to logging into the machine with a different profile and then test the Lync Client?


  • I have not. If the user have NEVER logged onto the PC AFTER the installation of Lync has occurred then the user can successfully log into Lync. If the user has logged onto prior to the install of Lync then the user cannot log into Lync. For example, I can log onto Lync successfully on my PC. But if I log onto the PC that is having the issue I am unable to log onto Lync because I have logged onto that PC before.

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