https://devzone.nordicsemi.com/f/nordic-q-a/24530/buttonless-dfu---led-3-blinking-after-flashWith SDK 14: If I flash in this order: softdevice_s132.hex bootloader_secure_ble_debug_ with bonds_s132.hex 3. ble_app_buttonless_dfu with _bonds_s132_with_setting_page.hex Then complete a DFU with this application: ble_app_buttonless_dfu_en-USTelligent Community 13Mon, 18 Sep 2017 13:12:41 GMThttps://devzone.nordicsemi.com/thread/96564?ContentTypeID=1Mon, 18 Sep 2017 13:12:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b4a8a43e-2d48-4d0f-bb60-d7bcbec7823cbjorn-spockeli<p>You&#39;re merging the settings hex with the application hex and then creating a zip file with the resulting hex file. The settings page should be merged with the bootloader hex-file and then flashed to the device along with the application that the settings file was generated from. It is not necessary to merge the settings hex with the bootloader hex when you&#39;re performing a DFU since the bootloader will update the setting page based on the information in the init packet.</p> <p>In short - Create a firmware image(.zip) with the application hex only.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/96563?ContentTypeID=1Wed, 30 Aug 2017 05:59:55 GMT137ad170-7792-4731-bb38-c0d22fbe4515:223a69c6-27b5-4477-aae3-9727b1b2098ddjqtsg<p>Have you checked UART log message? It may tell you what&#39;s going on</p><div style="clear:both;"></div>