Atmel Studio 7 requires specific information to support devices. This information is contained in versioned packs. For the AVR128DB48 Curiosity Nano board, Atmel Studio 7 version 7.0.2397 with device family pack “AVR-Dx_DFP” version 1.1 or newer are required. For more information on packs and how to upgrade them, refer to the Atmel Studio 7 User Guide - Device Pack Manager.