https://devzone.nordicsemi.com/f/nordic-q-a/82975/serial-dfu-on-nrf9160-dk-fail-to-upload-image-using-mcumgrHi, I try to implement Serial DFU update using the info in the &quot; Add DFU support to your application &quot; at link https://devzone.nordicsemi.com/guides/nrf-connect-sdk-guides/b/software/posts/ncs-dfu?CommentId=96ae5263-08cc-4a08-847c-50f1c1f17657 Theen-USTelligent Community 13Tue, 21 Dec 2021 07:39:51 GMThttps://devzone.nordicsemi.com/thread/344490?ContentTypeID=1Tue, 21 Dec 2021 07:39:51 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a961c271-4d89-40d5-9fdf-8f11459f9300H&#229;kon Alseth<p>Hi,</p> <p>&nbsp;</p> <p>Could you try setting this in prj.conf:</p> <p><pre class="ui-code" data-mode="text">CONFIG_HEAP_MEM_POOL_SIZE=2048</pre></p> <p>&nbsp;</p> <p>And see if it starts to work?</p> <p>I have recently debugged this same issue, and reported it internally to the developers.</p> <p>&nbsp;</p> <p>Kind regards,</p> <p>Håkon</p><div style="clear:both;"></div>