I want to play files on a USB stick that is connected to the USB input on the back of my Aries with Roon. I can play the files on the USB stick from the Aries Lightning DS App, but I can’t to get Roon to see the USB stick on the Aries.
Roon does sees the Aries as a Roon Ready Device, and sees/plays my Tidal playlists just fine through it.
Any help with this would be greatly appreciated
Your network must first recognize and mount the stick. Once it is recognized on your network it should be able to play the tracks.
Since Roon doesn’t see the stick to begin with, how do I mount it?
The Aries sees the stick, right? Do you really need a sophisticated database driven application to play a few files on a stick?
When I have files on a stick to play on my Oppo I just play them, no need for Roon.
Roon catalogs the stuff on the core or server so, as the other poster pointed out, it first has to be mounted on the core. To do that, the Aries would somehow have to become a file server seen by your core. There may, or may not, be a way to do that but even if it were, is it really worth the trouble? Roon would have to update your library and, as soon as you unplugged the stick, update it again.
What system is Roon running on? Mac? Windows? Linux?
a USB HD connected to an Aries can be seen on the network as a share
try adding it in Roon Storage/Add Folder typing "\\usbstickname"and see what happens
though… David, here above, is totally right 
To answer John’s question - Roon is running on a Window 10.1 laptop.
Regarding why I want to use Roon to play the USB stick on my Aries? The only reason is because I really don’t like using the Lightning DS App for controlling the Aries. The interface is not nearly as nice, and it hiccups/hangs at times causing me to have to reboot the App to clear it up.
That being said, if controlling the USB stick with Roon presents more problems than it solves, than I may stay with the Lightning DS App after all, when playing files off the USB stick.
I was able to add the USB stick on the Aries as a network share, and Roon did pick it up and added it to music files in the 2 folders on stick into the library. The problem now is I can’t get Roon to give me a folder view of the files on the USB stick. The music in these folders were given to me, and I want to go through them to familiarize myself with it. Not being able to access these files via a folder view, essentially rules out my being able to find them (easily) with Roon.
Am I missing something with not being able to get Roon to present folder views on my USB stick? If not, I guess I should just stick with the Lightning DS App in this case as suggested…
Roon does not have folder view 
You can assign a tag to the albums on the USB stick then filter using it
Thank you! I will definitely give that a shot.
During my excitement in installing Roon, I let it automatically create a library from Tidal based on genres of Music I told Roon I was interested in. Little did I realize that Roon was going to import close to 20,000 tacks, most of which I am not even familiar with.
What this has also done is obscure the few hundred tracks I personally created in my Tidal collection (so far) when browsing through my music collection.
Is there anyway to roll back the 20k Roon selected tracks (without having to re-install Roon) so I can start out with the Tidal tracks I created and manually build up my Roon library from there?
Perhap better is: in album view select ‘Focus’ > inspector > file locations
then bookmark this focus. It’s dynamic so if you add or delete files from the stick the bookmark/focus reflects the changes.