Thanks Jeffrey,
I used an alternative workaround 
I got our firewall team to temporarily grant the server direct access (one way) to the internet. This didnāt fix the issue immediately, so last night I left the server at the āSupport pageā feeling rather deflated, returned this morning, click ānoā, and voila! it moved onto the main DSP page
I will keep the above workaround that you have documented (many thanks for this) as once the DEV system is proven and accepted by our internal security team, I will be pushing for a Prod server installation, and then want to sign up for support.
Many thanks again.
Andy.