Hi, so I might take a little look by myself then!

I'll come back later if I've changed something ahah!
EDIT: Took me like 5 minutes to find it and fix it. Here's the line of code you need to add:

Found in the file SubsonicRestWeb.cs. I have noted videos aren't supported, but I don't really care. The thing is, your program won't support multiple folder architecture. What I mean is, if we have a folder into a folder, UltraSonic can't handle it. Hey don't give up this beautiful project, you are doing a great job! It's probably (and by far) one of the most cleanest source code I ever saw. Even in enterprise, a lot of people are programming like shit (speaking of personal experience here). I might give you some help if you want! Just PM me if you feel to! I might not have a lot of time, but when I do, I can help a lot!