https://devzone.nordicsemi.com/f/nordic-q-a/47824/serial-dfu---failing-on-execution-of-init-packHi @ all, I am trying to get the serial DFU process runnning. The process worked fine for nrf52832 and now I am on the nrf52840. I encountered a problem with executing the init-package. The following process is done fine: 1. Get MTU - set PRNen-USTelligent Community 13Tue, 28 May 2019 14:05:39 GMThttps://devzone.nordicsemi.com/thread/189676?ContentTypeID=1Tue, 28 May 2019 14:05:39 GMT137ad170-7792-4731-bb38-c0d22fbe4515:bbe3f9a8-8131-4de3-9435-2ca7913e9567HaDinh<p>Thank you! I mixed up the firmwarefile with one for the nrf52832 with a different SD. Choosing the right file is complicated sometimes... Best regards!</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/189572?ContentTypeID=1Tue, 28 May 2019 10:47:58 GMT137ad170-7792-4731-bb38-c0d22fbe4515:82360b67-87c6-42c2-b888-986d1549bb1bHung Bui<p>Hi Ha,</p> <p>If you have a look inside the code you can find error code 0x0b =&nbsp;&nbsp;NRF_DFU_RES_CODE_EXT_ERROR inside nrf_dfu_req_handler.h&nbsp;</p> <p>The extended error code is listed inside nrf_dfu_ext_error_code_t in nrf_dfu_handling_error.h. Code 0x07 meaning :</p> <p>NRF_DFU_EXT_ERROR_SD_VERSION_FAILURE = 0x07, /**&lt; The array of supported SoftDevices for the update does not contain<br /> the FWID of the current SoftDevice or the first FWID is &#39;0&#39; on a<br /> bootloader which requires the SoftDevice to be present. */</p> <p></p> <p>Could it be that you used the wrong SD version, doesn&#39;t match with what on the nRF52840 ?&nbsp;</p> <p>You can add a breakpoing inside&nbsp;sd_req_ok() to check what exactly went wrong.&nbsp;</p><div style="clear:both;"></div>