nrfutil device program - Unable to open device

RE: nrfutil device program - Unable to open device

Distromel — Wed, 27 Aug 2025 06:23:54 GMT

I'm just starting with Thingh91X. I've followed the fundamentals tutorial without problems.

Now I'm trying to generate a multithreading project but when I'm going to program the device I get the following error:

PS C:\myfw\ncsfund\workspace\threads> nrfutil device program --firmware dfu_application.zip --serial-number THINGY91X_5FBB616A50D
Error: Firmware does not exist dfu_application.zip

RE: nrfutil device program - Unable to open device

smmx — Wed, 09 Jul 2025 06:22:11 GMT

I managed to solve the issue, but I would suggest to help new users in some way, such as add notification when starting to program in multiple docs.

https://www.nordicsemi.com/Products/Development-tools/nrf-util
I followed Prerequisites and opened
https://docs.nordicsemi.com/bundle/nrfutil/page/guides/installing.html#prerequisites
then I followed and installed nrf-udev from https://github.com/NordicSemiconductor/nrf-udev/releases/tag/v1.0.1

After replugging device, it worked.

RE: nrfutil device program - Unable to open device

smmx — Wed, 09 Jul 2025 05:51:57 GMT

If I run

sudo /home/smmx/.local/bin/nrfutil device program --firmware build/dfu_application.zip --serial-number THINGY91X_46EEE983CDD --traits mcuBoot --x-family nrf91 --core Application

then I can flash successfully. Any chance to know which permission is missing? I tried to log to file but did not find anything helpful yet.