https://devzone.nordicsemi.com/f/nordic-q-a/37433/sdk-v15-dfu---update-bootloader-zip-file-failHi I used nrfutil.exe (v3.5.1 based on python v2.7.13) to create bootloader.zip file from SDK v15 - \dfu\secure_bootloader\pca10040_ble\ sample code. CMD : nrfutil.exe pkg generate --hw-version 52 --sd-req 0xA8 --bootloader nrf52_bootloader.hex -en-USTelligent Community 13Wed, 15 Aug 2018 16:42:29 GMThttps://devzone.nordicsemi.com/thread/144378?ContentTypeID=1Wed, 15 Aug 2018 16:42:29 GMT137ad170-7792-4731-bb38-c0d22fbe4515:0b591abd-7d79-40c1-82b2-b075396d5d73Sigurd<p>Hi,</p> <p>Is this the error message you get?</p> <p>Image from nRF-Connect desktop:</p> <p><img alt=" " src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/communityserver-discussions-components-files/4/71114.error.png" /></p> <p><span>This generally means that the public key in the bootloader and the private key used to sign the DFU image does not match.</span></p> <p><span>Please make sure that you are using the correct private key, and try again.</span></p> <p><span></span></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/144034?ContentTypeID=1Tue, 14 Aug 2018 02:15:58 GMT137ad170-7792-4731-bb38-c0d22fbe4515:c17df96b-53c7-488c-80e3-85678b911883Atlas<p>Hi&nbsp;</p> <p>I also used the files that are in&nbsp;\examples\dfu\secure_dfu_test_images\ble\nrf52832\ to test.</p> <p>It works well when updates SD zip and Application zip but it is still fail on bootloader zip file updated.</p> <p>Please help to check this issue.</p> <p>Thanks.</p> <p>BR</p> <p>Atlas</p><div style="clear:both;"></div>