On Filemaker Server 16 I created a certificate request, uploaded to my certificate authority Comodo . Comodo issued a zip file that contained several files one is my order number as filename with extension .crt
I went back into Filemaker server and browsed to this file as the signed file, and in the private key file put the serverRequest.pem file but get the error
certificate could not be imported: the private key file already exists, please remove it and run the command again
I am also putting in the Private Key Password not sure what I am doing wrong
serverRequest.pem is not your keyfile, when you generated the original request it should have downloaded a serverKey.pem file for you as well which is what you need to put there.
serverKey.pem is different and should never be shared with the SSL provider.