The latest desktop controller update has a bug preventing a successful music library setup. When you select the option to setup the music library, choose network device, and click the add button, you are prompted for the path to the music. Once you enter it and click 'Next' it prompts you for the ID and password of the NAS. You can no longer click the 'next' button without entering something in the ID and password fields.
As a workaround, you can enter a single letter in each field and the next button becomes available. You can then delete the values and the next button remains available.
This is the Windows version. Not sure if the Mac version does it.