https://devzone.nordicsemi.com/f/nordic-q-a/4765/how-to-debug-the-custom-nrf51822-board-through-segger-j-linkHi, I am using custom nrf51822 board. I am trying to debug through JTAG(segger j-link). While downloading the program into flash, I am getting error like &quot;Error: Flash Download failed - Target DLL has been cancelled&quot; . I have changed the settings fromen-USTelligent Community 13Tue, 16 Dec 2014 09:21:08 GMThttps://devzone.nordicsemi.com/thread/16861?ContentTypeID=1Tue, 16 Dec 2014 09:21:08 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f572703d-7439-4a9a-a362-e5435bf1ca56Petter Myhre<p>The most common reason for this error is that you are trying to flash an application on top of a SoftDevice.</p> <p>It is difficult to determine the reason of the error by the error alone, it would be helpful if you could include what you did before you got the error. What SDK, SoftDevice, and example you are using could also be of help. Please edit your question to include this, if the error persists.</p><div style="clear:both;"></div>