Use : https://whatsmychaincert.com/ to check your chain is correct  :

or Download and Run the “Digicert Certificate Utility: and go to Tools , then Check Install

Enter the URL link and make sure the URL is coming back with 2 Certs , the top one should be your cert and there should be a Root Cert underneath

If one one cert if coming back , go into your Netscaler , Go to Configuration , Traffic Management , SSL , Certificates, Server Certificates and Link your SSL Cert there to a root one by right clicking and choosing Link

A manual way

Export the .cer files for the certificate using Internet Explorer ( Run as Administrator to Copy to file otherwise it will be greyed out ) and also the Root CA for that cert

Put these somewhere the Mac can access like a dropbox folder

Install the Certs to the Mac’s keychain