installation of SSL Certificate with Intermediate Certificate

My production Filemaker Server 14 running on Mac OS X 10.11 El Capitan (Not Mac OS X Server) has been running fine for a year since I last installed the Thawte SSL Certificate.  After renewing the certifate this year, I've tried various different methods of importing the new certificate, which came with an intermediate certificate, but I can't seem to get the intermediate certificate installed.  I've been mostly using something like:

sudo fmsadmin certificate import --keyfile /Users/richardfincher/Desktop/GBROOMX36-4X/private.key /Users/richardfincher//Desktop/GBROOMX36-4X/ssl_certificate.crt

I've also tried importing it through the web control panel.  It was necessary to remove the old private key thus.:

sudo rm /Library/FileMaker\ Server/CStore/serverKey.pem

After it is (apparently) installed, I usually restart with :

sudo fmsadmin restart adminserver

although a few times I have rebooted the server (not a VM)

Any thoughts welcome....

Oh, one thing is, a year ago it might have been still on Mac OS X 10.8.5 Mountain Lion, which was the previous OS before I upgraded it.