Hi Greg & BlackJack,
I eventually figured out what the issue was. Yes, I’m using File Explorer to find the share. However, you also need to turn ON the SMB file sharing feature in Windows under Control Panel, Programs. After I did that and rebooted the various Rock folders were visible and accessible via File Explorer. I’ve copied the ffmpeg codecs file to /Data/Codecs folder and everything looks good in the Rock web UI now. Internet Explorer no longer renders the Rock Web UI properly. Using MS Edge or Chrome displays fine. The Roon Server Software status now reports OK. Thanks.
Chris