https://devzone.nordicsemi.com/f/nordic-q-a/124722/trouble-getting-mcuboot-signing-working-with-ncs-v3-1-0-app-won-t-startHi, I’m trying to enable signing with MCUboot in my NCS v3.1.0 project, but I can’t get the app to start once I turn on signing. The build succeeds, I flash build/merged.hex, the app doesn&#39;t run. Without signing it runs fine. Any guidance would be muchen-USTelligent Community 13Thu, 02 Oct 2025 11:18:25 GMThttps://devzone.nordicsemi.com/thread/550460?ContentTypeID=1Thu, 02 Oct 2025 11:18:25 GMT137ad170-7792-4731-bb38-c0d22fbe4515:8391874f-89be-4aa6-916b-3517c255260bDanielNG<p>Hi, you don&#39;t need these in mcuboot/prj.conf. Please refer to&nbsp;<a href="https://academy.nordicsemi.com/courses/nrf-connect-sdk-intermediate/lessons/lesson-9-bootloaders-and-dfu-fota/topic/exercise-2-dfu-over-usb-adding-external-flash/">Exercise 2 - DFU with custom keys - Nordic Developer Academy</a><br /><br /><pre class="ui-code" data-mode="text">mcuboot/prj.conf CONFIG_BOOT_SIGNATURE_TYPE_RSA=y CONFIG_BOOT_SIGNATURE_KEY_FILE=&quot;/opt/nordic/ncs/v3.1.0/apps/myapp/keys/root-rsa-2048.pem&quot;</pre><br /><br />You can keep your sysbuild config.<br /><br />Please add some mcuboot logging and send over the logs if you are still having issue (create a sysbuild/mcuboot.conf and add CONFIG_LOG=y)</p><div style="clear:both;"></div>