6 August 2013

problem verifying certificate

When trying to sign in to Lync get the following error:
There was a problem verifying the certificate

It's either a certificate trust issue or a DNS name mismatch to the certificate that you have issued.  
The PC or device which you are using to logon to Lync needs to trust the certificate chain from which you generated the Lync certificate(s) and the DNS records used to locate and connect to the Lync server need to match the name(s) on the certificate.

In my case I was using Manual Login and pointed to the IP address which was obviously not in the certificate :p


  1. So you ran an ipconfig/ flushdns, selected the Lync to AUTO and that was it?

  2. In my case I switched to using the DNS name instead of IP. However a much more common cause if this issues is experienced when the client PC is not joined to the domain. In that case you need to add the root CAUSE to the trusted cert store