Hello World, Unable to find bootable image

[BvdP4Celsius]

I notice a problem with the MCUboot Hello World example.

I followed the steps mentioned in https://www.mcuboot.com/documentation/readme-zephyr/
That is, build the MCUBoot application with VSCode and nRFconnect 2.0.0 and flashed the hex-file to the nRF52840 DK with the nRF Programmer V3.0.3.
Address range is 0x00000000-0x00008247.
The build the Hello World example from mcuboot\samples\zephyr\hello-world  and flashed the hex-file to the nRF52840 DK. 
Address range is 0x0000C200-0x00011AEB.
After a reset I see the following in the terminal:

*** Booting Zephyr OS build v3.0.99-ncs1 ***
I: Starting bootloader
I: Primary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
I: Secondary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3
I: Boot source: none
W: Failed reading image headers; Image=0
E: Unable to find bootable image

What could be the problem here?

[Amanda Hsieh]

Hi, 

flashed the hex-file to the nRF52840 DK with the nRF Programmer V3.0.3.

Do you flash the merged.hex under build\zephyr?

Why don't you use VScode flashing images to DK?

Regards,
Amanda