Thanks for your assistance in resolving this, it is appreciated!
Yes, I have rebooted, multiple times after each unsuccessful static/dynamic/reset to default IP changes. The thing will respond to ALL pings regardless of IP change from varuious hosts an dit returns correct ping when tested from the console against other machines. However web admin and browsing of the network remains lost. A port scan of the machine shows 443 & 135 not present. It is almost like all the services are either not running at all or thinking they are on listening on a different NIC (I have only one).
To answer your question what was I doing, at the time of lock up I had clicked on of the upper Admin menu options, I think it was the status menu. I was connected in the first place to check the disk space. Upon login the initial page displayed the Not Registed page (along with the Activated status) that triggered my ToDo item which was get this thing registered since it had failed on previous attempts. I tried it again and it just returned a terse red "Error" without any cause. When I was looking for the disk summary I noticed the SMART status, saw that it was not enabled and went looking for that. Also, I noticed that the antivirus was showing that it was stale or something so I went ahead and downloaded a fresh update. That worked without issue. I *think* I next went into networking looking for any reason why this registration would not work (despite the successful reach out for new A/V definitions). I remember clicking the update on the networking IP settings just to force an update. Then I went off looking for this SMART setting and while I was reviewing the various admin menu options the web just crapped out. The ongoing file transfer continued and I could still see/access the device.
As a side topic, this is good time to ask "how do I recover"? This was set up initially as a proof of concept for a customer demo & expected install (of the 4TB version) and only had test data but it has been running so well and reliably that admittedly it became a rather trusted friend and consequently I did move some content I would like to recover if I need to start from square one again!!! If I cannot get this device usable without a complete reinstallation (ie: wipe) is the content of the drives readable/salvageable by another linux system if removed & re-installed on the Linux PC? It is a simple software raid 1 setup.