I'm writing a UWP Music player, that syncs Music stored in your OneDrive to the local machine to play it. The User can Store it in the App folder, or his Music Folder.
I also would like that this app runs on the XBoxOne. Unfortunately Storing Data on the System will quickly throw Not Enough Disk Space Exception.
According to an MSDN Answer an app can have a maximum of 3GB and there seems to be ways to get it up to 16GB if no other UWP app takes up that space.
A dedicated Music folder is not available on Xbox. (The method to get the StorageFolder returns null)
Is there any way to store more data on the Xbox? Some music library's exceed easily 50GB.
No, there is no support for apps to get additional space on the internal drive (there can be a user music folder, but space here is limited). The reason why you got a failure getting the music folder may because that you didn’t declare the capability. Since given the limited storage, I’d strongly discourage you from writing files there.
You can format an external USB drive to be used for media playback and plug it in, with apps being allowed to read from it if you have the capability defined in your manifest.
https://learn.microsoft.com/en-us/windows/uwp/packaging/app-capability-declarations
See above for declaring access to removable storage if you want to read from an external drive formatted for media.
Thanks.