https://devzone.nordicsemi.com/f/nordic-q-a/94037/recover-bootloader-on-pca10059---invalid-hex-fileI recently bought a pca10059 and inadvertently erased the bootloader while using a script from another project.. (it did --recover unfortunately). I&#39;m using the debug out port on a pca10056 for swdio/swdclk; I have 3v0 to VDD_OUT and &#39;nrfjprog --deviceversionen-USTelligent Community 13Fri, 18 Nov 2022 17:27:21 GMThttps://devzone.nordicsemi.com/thread/396481?ContentTypeID=1Fri, 18 Nov 2022 17:27:21 GMT137ad170-7792-4731-bb38-c0d22fbe4515:893dc5df-b1e8-4748-9069-a58f3efde7c7hpeyerl<p>Never fails.&nbsp; Fight with something for 2 days, finally post the question, then an hour later figure it out.<br /><br />The key was the NRF52840_xxAA_REV3 vs my other boards are NRF52840_xxAA_REV2.<br /><br />The solution is to install a new nrfjprog.&nbsp; I had 10.12.1.&nbsp; I installed 10.18.1 and all is well.</p><div style="clear:both;"></div>