Running AR 2.0 on port 443 (SSL) behind Access Manager.

AR and IDMApps/OSP are using eDirectory issued certificates.

AR is integrated with IDM/OSP.
OSP is integrated with Access Manager using SAML2.

After logging into AM and being redirected to AR I see the top header on
the page: "NetIQ Access Review"

Below we have a spinning circle and the message:
"An error occurred while attempting to contact the authentication service."

According to Firefox we get the error on the request to the following
URL: https://hostname/api/whoami

{"Fault":{"Code":{"Value":"Receiver","Subcode":{"V alue":"AuthServerUnavailable"}},"Reason":{"Text":" An
error occurred while attempting to contact the authentication service."}}}

In the localhost_access_log.2016-08-31.txt file I can see:
xxxxxxxxxxx- - [31/Aug/2016:15:19:21 +0200] "GET /api/whoami HTTP/1.1"
503 188

I have the AM root certificate in the cacerts file on both the OSP/IDM
server and on the AR server. Also the eDirectory tree cert that issued
the certs for AR/IDMApps is imported into the cacerts files on both servers.

In configupdate on the Authentication tab I have pointed the Optional
TLS/SSL truststore file to the same cacerts file.