https://devzone.nordicsemi.com/f/nordic-q-a/127835/legacy-dfu-failure-on-newer-appWe have a product created with the BMD350 from Ublox (formerly Rigado). It is based on the nRF52832. it uses SDK 12 and implements the Legacy DFU. Updating to a newer SDK is not an option. We have a cross platform mobile app that has implemented theen-USTelligent Community 13Fri, 17 Apr 2026 20:44:06 GMThttps://devzone.nordicsemi.com/thread/565125?ContentTypeID=1Fri, 17 Apr 2026 20:44:06 GMT137ad170-7792-4731-bb38-c0d22fbe4515:de05ab5a-1fa1-437a-90c3-f0b1cef3fd35Amanda Hsieh<p>Happy to know you found the issue. <span class="emoticon" data-url="https://devzone.nordicsemi.com/cfs-file/__key/system/emoji/1f642.svg" title="Slight smile">&#x1f642;</span></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/565123?ContentTypeID=1Fri, 17 Apr 2026 20:12:04 GMT137ad170-7792-4731-bb38-c0d22fbe4515:ec35a42d-fb1c-4999-8fe9-d82e17ce7d02Tony<p>I decided to look through our firmware code and found what is going on, so disregard this post.</p> <p>Turns out we have our own check to see if there are more messages in the queue to go from our device to our app and if there are we indicate we are not ready to go into DFU boot loader.</p> <p>This code was written a long time ago by someone else, so I was not aware of this.</p> <p>I guess the new app sometimes still has pending data coming from the module when we issue the DFU request and that is killing it.</p><div style="clear:both;"></div>