Lync Edge 2013 Certificate Assign (again!)

Question

Hi,
I recently posted a similar topic on the forum (Lync
Edge 2013 Certificate Assign). The issue was related to certificate assignation. I solved it, but I needed later to change my certification authority, and so change the certificate assigned to the public Edge interface. Trying this, I encountered a new
(different) problem with my new certificate, so I am back here to try to find a solution.
As said, I am trying to assign a Certificate to my Lync 2013 Edge Server on the Internet edge.  This certificate is signed by a recognized authority (Comodo).
Whenever I imported the certificate in the store via the Lync wizard and proceed on to the Assign Certificate step, the Certificate that i have imported does not appear in the List of certificates on the Lync deployment tool interface, so that I cannot assign
it to the External Edge interface.
I tried to import it with Digicert (which allow me to solve my previous importation problem, but not this time...) with no more result.  I tried to import it from cer format, or crt format, results are the same.
I launched the MMC on the computer and add the Computer Certificate Snap-In. If I look at the certificate icon, I see the little key in the icon, so it sounds like I have the private key available.
Any help would be greatly appreciated!
Thank you very much for your help.
EDIT: when running the digicert tool "Test Key", the result is the following : " the private key was successfully tested" and "revocation check for certificate chain failed". Does it give any clue ?

Answer 1

I had the feeling I did everything fine too...!  This is maybe a silly question, but I try anyway: do you think it be possible that I cannot choose the imported certificate by the Lync Deployment assistant because the assistant does not recognize the
public name of the computer? I mean, I could add the internal interface certificate because the computer recognized its local name (edge.local.domain). But it seems he doesn't know its Internet FQDN (lync.mydomain.com) which is mentionned in the topology.
It does not explain why I could previously add the wilcard certificate, so I think my remark is silly, but I am kind of lost....
Thank you anyway for your messages.
EDIT: when I try to use powershell to assign manually my certificate, i got an error message telling that the command execution failed because [my certificate thumbprint] is not in the store or not approved. It is true that I had some intermediate certificate
provided by Comodo, but I installed all of them in the store via mmc>Certificate, both in trusted root CA and intermediate CA. Maybe I miss a location ?