when I run through https://testconnectivity.microsoft.com and do the Lync test for logging in we get:

Couldn't sign in. Error: Error Message: A certificate chain processed, but terminated in a root certificate which is not trusted by the trust provider.
Error Type: TlsFailureException.

We use a mix of Comodo (wildcard certificate on reverse proxy) and Terena (san certificate on edge) certificates.  Can login fine etc. just concerned that these checks are failing.

The autodiscovery test passes fine etc.

Can anyone advise please?

Put chain of certificate in correct container. Root in trusted root certificate authority. Intermediate in Intermediate certificate authority.

Hi Evotel2015,

The Remote connectivity tool is a relatively old tool, the test failure by this tool doesnt mean Lync client login will not work as expected.

And the authenticated UC certificate partners for your reference.

https://support.microsoft.com/en-us/kb/929395

Best regards,

Eric

wouldn't the ms side need the root in the correct place as they are testing the connection?

thanks Eric. Comodo are listed so don't think its that....maybe im missing the root on my edge box?

Hi Evotel2015,

In my opinion, the intermediate CA certificates "TERENA SSL CA" might not be installed on MS side.

Best regards,

Eric

Ive had this issue in the past with Go Daddy - they introduced a new CA which MS did not current support in their list of trusted CA's. I ended up asking Go Daddy to sign the cert with the old CA and the issue went away.

If you are not having any issues signing in or federating with others, then you probably dont need to do anything.