Error message when you try to sign in to Lync 2010 after a network outage or a Lync Online service outage: "Cannot sign in to Lync"

Article ID: 2698626 - View products that this article applies to.

Not sure what release of Office 365 you're using? Go to the following Microsoft website:
Am I using Office 365 after the service upgrade?
(http://office.microsoft.com/redir/HA103982331.aspx)
Expand all | Collapse all

PROBLEM

When you try to sign in to Microsoft Lync 2010 after a network outage or a Microsoft Lync Online service outage, you receive the following error message:
Cannot sign in to Lync. You may have entered your sign-in address, user name, or password incorrectly, or the authentication service may be incompatible with this version of the program. If your sign-in information is correct and the problem persists, please contact your system administrator.
Back to the top | Give Feedback

SOLUTION

To resolve this issue, follow these steps:

Step 1: Update Lync 2010

Update Lync 2010. To do this, visit the Microsoft Update website
(http://update.microsoft.com)
, and then install any updates that are available for Lync 2010. Updates are available for Lync 2010 that prevent this issue.

If the issue isn't resolved after you update Lync 2010, go to step 2.

Step 2: Refresh Lync cached endpoints

To have us refresh Lync cached endpoints for you, go to the "Fix it for me" section. If you prefer to refresh Lync cached endpoints yourself, go to the "Let me fix it myself" section.


Fix it for me

To refresh Lync cached endpoints automatically, click the Fix it button or link. Then, click Run in the File Download dialog box, and follow the steps in the Fix it wizard.

For Windows 8

Collapse this imageExpand this image
Fix this problem
(http://go.microsoft.com/?linkid=9828780)

Microsoft Fix it 20089
Collapse this imageExpand this image


For Windows 7, Windows Vista, Windows XP, Windows Server 2008, or Windows Server 2003

Collapse this imageExpand this image
Fix this problem
(http://go.microsoft.com/?linkid=9800329)

Microsoft Fix it 50799
Collapse this imageExpand this image


Notes
  • This wizard may be in English only. However, the automatic fix works for all language versions of Windows.
  • If you aren't on the computer that has the problem, save the Fix it solution to a flash drive or a CD, and then run the Fix it solution on the computer that has the problem.

Then, go to the "Did this fix the problem?" section.



Let me fix it myself

When Lync 2010 connects to a specific front-end server, it caches that endpoint to make the sign-in process faster in the future. However, sometimes the endpoint can be changed. This can cause sign-in to fail. To delete the endpoint cache, follow these steps:
  1. Locate the local application data folder:
    • Windows Vista and Windows 7: %LOCALAPPDATA%\Microsoft\Communicator\<sip_address@contoso.com>\
    • Windows XP: %USERPROFILE%\Local Settings\Application Data\Microsoft\Communicator\<sip_address@contoso.com>\
  2. Delete the file that's named EndpointConfiguration.CACHE.
  3. Restart Lync 2010, and then try to sign in to Lync Online.

Did this fix the problem?
  • Check whether the problem is fixed.
    • If the problem is fixed, you're finished with these steps.
    • If the problem isn't fixed, see the following article in the Microsoft Knowledge Base article for additional troubleshooting steps:
      2541980
      (http://support.microsoft.com/kb/2541980/ )
      How to troubleshoot sign-in issues in Lync Online
      If the problem is still not fixed, visit the Office 365 Community website
      (http://community.office365.com/en-us/default.aspx)
      or contact support.
  • We would appreciate your feedback. To provide feedback or to report any issues with this solution, please leave a comment on the "Fix it for me
    (http://blogs.technet.com/fixit4me/)
    " blog or send us an email
    (mailto:fixit4me@microsoft.com?Subject=KB)
    message.
Back to the top | Give Feedback

MORE INFORMATION

When Lync 2010 connects to a specific front-end server, it caches that endpoint to make the sign-in process faster in the future. However, sometimes the endpoint can be changed. This can cause sign-in to fail.
Back to the top | Give Feedback

Still need help? Go to the Office 365 Community
(http://community.office365.com/)
website.
Back to the top | Give Feedback

Properties

Article ID: 2698626 - Last Review: May 15, 2013 - Revision: 12.0
Applies to
  • Microsoft Office 365 for enterprises (pre-upgrade)
  • Microsoft Office 365 for small businesses  (pre-upgrade)
  • Microsoft Office 365 for education  (pre-upgrade)
  • Microsoft Lync Online
Keywords: 
kbfixme kbmsifixme o365a o365 o365e o365p o365022013 after upgrade o365062011 pre-upgrade o365m KB2698626
Back to the top | Give Feedback

Give Feedback

 
Back to the topBack to the top