https://test-devzone.nordicsemi.com/f/nordic-q-a/88597/jlink-ctrl-ap-indicates-that-the-device-is-securedHI, I am start use NRF52840DK(rev3) to devlopment usb application，but jlink always show this information I try to use &#39;nrfjprog --recover&#39; to disable read protection, then program application hex file, but jlink again show inforamtion when deviceen-USTelligent Community 13 Non-ProductionTue, 07 Jun 2022 06:50:35 GMThttps://test-devzone.nordicsemi.com/thread/371032?ContentTypeID=1Tue, 07 Jun 2022 06:50:35 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f3f19808-fa20-49e1-883e-0330c0de3e23user77782<p>Hi,&nbsp;</p> <p>Have a look at <a href="https://test-devzone.nordicsemi.com/f/nordic-q-a/85671/trying-to-disable-approtect-for-debugging/357402#357402">this post</a>. You could&nbsp;<span>try to call the&nbsp;approtect_hw_disable function provided in that thread at the beginning of main() to disable approtect in UICR.APPROTECT.&nbsp;</span></p> <p><span>Regards,<br />Amanda</span></p><div style="clear:both;"></div>