For future reference since you seem to have yours working for the vault 2 the page is
https://www.bluesound.com/products/vault-2/attachment/v510_usb_stick_3-2-6/
You have to fill out your information and they will email you a link to the download page. Looks like a network problem might try removing the NAS from the vault , adding it back and let the vault find it again ? Does the Node play from the NAS? Bluesound uses SMB not DLNA I think Oppo uses DLNA
https://www.bluesound.com/products/vault-2/attachment/v510_usb_stick_3-2-6/
You have to fill out your information and they will email you a link to the download page. Looks like a network problem might try removing the NAS from the vault , adding it back and let the vault find it again ? Does the Node play from the NAS? Bluesound uses SMB not DLNA I think Oppo uses DLNA