I haven’t seen much written about this, but there is a bit of an issue with upgrading the client and how it signs in to Lync.
First, some people will see the short-cut where they are used to seeing it on either the desktop or the taskbar. However, the short-cut doesn’t have the old Lync 2010 icon, it is just a blank icon. If you click on the blank icon, you will get this error message.
The biggest issue, though, is that most users will see the error that says they Can’t sign in to Lync, when trying to log into Lync 2013 the first time. that they try to open it. There are two potential fixes:
- Wait a few minutes and try again. Most likely, it will fix itself.
- Click on the Delete my sign-in info link and it will delete any existing certificates and allow a new certificate to be downloaded from the Lync servers.
The issue is a simple one. Lync 2010, before it was upgraded, was using a certificate that it received from the Lync server environment so that the client could use the certificate for easier authentication. The certificate isn’t valid for the new client installation, and needs to be replaced.
After resolving this issue, then you will most likely be prompted to enter your username and password. The standard user name for your organization is all that needed for the user name field. You can use the UPN, or you can also use the old style of DomainName\UserName format.
It is a good idea to provide a simple document to Lync users before the upgrade so they will not flood the helpdesk with too many calls that they can resolve themselves.