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Hopefully this will be my last request for help.
I've gone all the way through the OLSB migration to O365, migrated my customer domain and site which is now working, got Exchange Online working with my Outlook 2007 client but now find I cannot log into Lync.
I'm getting an "incorrect user name/password/domain" error mesage. Of course, my username and password work to login onto the admin dashboard.
The funny thing is that Lync was actually the first thing that worked in the O365 set-up but now has decided to be a problem.
Please note that I am a single user organisation.
Hope someone can give me the steps I need to put this right.
I understand that when trying to sign in Lync, an error message is received stating that “the username, password or domain appears to be incorrect.”
This issue can be caused if the cached credentials are corrupted．To troubleshoot this issue, please renew the certificate for Lync, and then test the issue again. You can refer to
If the issue persists, please continue to perform the steps below:
1. Delete the Crypto RSA key container.
1. Open Windows Explorer and locate the C:\Documents and Settings\<User>\Application Data\Microsoft\Crypto\RSA\ folder. (For Windows Vista and Windows 7, the location is C:\Users\<User>\AppData\Roaming\Microsoft\Crypto\RSA)
2. Delete the RSA key subfolder. The name of the RSA key subfolder consists of a long string of numbers and characters. For example:
3. Restart the computer, and then try to sign in to Lync Online. If the issue persists, please check the issue again by using the Step 2.
2. Refresh Lync cached endpoints
1. Locate the local application data folder:
Windows Vista and Windows 7: %LOCALAPPDATA%\Microsoft\Communicator\<\">firstname.lastname@example.org>\
2. Delete the file that is named EndpointConfiguration.CACHE.
3. Restart Lync 2010, and then try to sign in to Lync Online.
1 out of 1 people found this post helpful.
I followed support.microsoft.com/.../2604176 as you suggested and got the following:-
1. Updated Lync 2010 and client from download - login still didn't work
2. Updated the Microsoft Online Services Sign In Assistant to the latest version by running Office 365 Desktop from download - login still didn't work
3. Checked Communications Server certificate and found that it was still issued to origional 'onmicrosoft' user name and not my custom (domain) user name, deleted it - login now works.
Hopefully I won't have any more problems.
I’m glad to hear that the Lync sign issue has been resolved by deleting the original certificate. It was my pleasure to work with you. I would like to share the following websites with you. You may find some useful information about Office 365.
For Office 365 Enterprises:
For Office 365 Small Businesses: