Windows 10 USB link. NRF connect 3.6. Followed recommended instruction on extracting firmware. Pressed switch 3 in middle of board on power up. Device showed up in window. Clicked enable MCU boot. Got error: MCUboot DFU failed. Please make sure that the device is in MCUboot mode and try again. You can see the file version I was trying to load below. Sorry, I can't tell what serial number the board is. But it says: PCA20035 1.4.0 2020.22 I noted that several people have posted about this, but did not see any solutions in the threads. I do not have a segger debugger.
Thanks
Jim