It’s possible that he did but probably futile to try guessing
As I said to @francisco_gaston, you must follow the instructions and not do something else. We could help better if you could post screenshots of what you are doing when creating the bootable USB stick.
Fantastic, congratulations. I know it can be bewildering if it’s your first time installing any operating system.
Normally, you probably never have to do much with your ROCK again, it should be taking care of itself.
With this NUC and a good new PSU it is a significant improvement from old and as well with using Roon with the MAC
Now I am would enter in problems trying to install the extension to rip CD with NUC….
Note that ROCK supports ripping natively if you want that. Simply attach a CD/DVD reader by USB. You only have to insert the CD and the rest is automatic. No need for the extension solution. (The extension requires a separate computer, you can’t use it just with ROCK).
However, be aware that the ripping by ROCK is only useful if you are sure that you will never want to use the ripped files elsewhere. It does NOT name and tag the album folders and files with names, etc. It is purely for use of the files within ROCK. It’s great if you don’t mind that:
Personally, I prefer to rip on my PC. dbPoweramp is a great program for that (search the forum and you will find much information). It downloads metadata from MusicBrainz and other sources, so that files will be properly named and tagged; you can also edit the metadata before starting the rip. It has secure ripping options and checks the result by comparing it to other rips of the same CD in the AccurateRip database. If the result matches the same CD that was ripped by many other people you can be sure that it ripped perfectly.
After ripping on the CD, I transfer the files over the network to the ROCK: