The "BootLDrUSBFS" and "USBFS" user modules cannot be used together. However, your application can be implemented with just the BootLDrUSBFS as it gives you option to develop USB code also. BootLDrUSBFS includes all functions of USBFS and you can implement all functionalities of USBFS using this user module. Place the BootLDrUSBFS user module and right click on it and run the "Device: Application USB Setup Wizard" for developing USB code. For Bootloader code, you can run the "Device: Bootloader USB Setup Wizard". A screenshot is attached for your reference.