Lync Server Deploy Certificate Verification Failed

certificate-authoritylyncssl-certificatewindows-server-2008-r2

Just got my Lync server deployed on Windows Server 2008 R2 and am trying to connect via Lync client on a different machine. When attempting to sign in, the client throws an error saying "Cannot sign in to Lync: There was a problem verifying the certificate from the server.".

Looking deeper, into the client box's event viewer, I see the following error "The certificate received from the remote serer was issued by an untrusted certificate authority. Because of this, none of the data contained in the certificate can be validated. The SSL connection request has failed. The attached data contains the server certificate. ….

My organization has an internal CA, which is in charge of issuing all required certificates to the Lync server. My client box has installed the internal CA (root) as a trusted CA provider. To me, this should cause any certificates that issues, including the Lync certificates, to be trusted.

I installed Lync client on the same box that Lync server is hoted, and am able to log in fine. My error only occurs when connecting from another box.

Can someone shed some light? Thanks!

Best Answer

Maybe your server is using a self-signed-cert rather then one issued from your CA.

What certificate did you assign with the Lync server Certificate Wizard in the deployment wizard? That's the one the client's will see when connecting. If you used the same certificate for all three services in the Certificate Wizard, then you can test if the client trusts the cert or it's root by web browsing to the web services URL from the client machine i.e. pull up the admin console: https://hostname.domain.com/cscp for standard Ed or enterprise ed: https://poolname.domain.com/cscp

In IE you can actually look at the cert the server is sending to the client and view any warnings the client has about the cert (I don't know how to see the incoming certificate from Lync client).