nrfutil cannot recognize J-Link, preventing flashing with nrfutil and preventing VS Code from recognizing the device.

RE: nrfutil cannot recognize J-Link, preventing flashing with nrfutil and preventing VS Code from recognizing the device.

Einar Thorsrud — Mon, 15 Dec 2025 11:56:07 GMT

I see. Then I suggest you first test with Windows 11 in the VM, as Windows 11 is fully supported. There are still no guarantees that it will work there though, as virtual machines is not directly supported (there are multiple vendors of virtualization and it can be configured in different ways, so it is difficult for us to support all combinations).

RE: nrfutil cannot recognize J-Link, preventing flashing with nrfutil and preventing VS Code from recognizing the device.

zero — Mon, 15 Dec 2025 01:56:33 GMT

Hi,

For confidentiality reasons, we can only use this "cloud desktop" virtual machine and cannot switch to a physical Windows 11 machine. Please help analyze how to solve this problem.

BR，

Zero

RE: nrfutil cannot recognize J-Link, preventing flashing with nrfutil and preventing VS Code from recognizing the device.

Einar Thorsrud — Fri, 12 Dec 2025 15:10:41 GMT

Hi,

I see. Virtual machines can be problematic, and nrfutil (which is also used by nRF Connect for VS Code) is no longer tested on Windows 10 (see Supported operating systems). I recommend using Windows 11 on a physical machine.

RE: nrfutil cannot recognize J-Link, preventing flashing with nrfutil and preventing VS Code from recognizing the device.

zero — Fri, 12 Dec 2025 01:03:33 GMT

It can be considered a virtual machine, except that it runs Windows 10.

RE: nrfutil cannot recognize J-Link, preventing flashing with nrfutil and preventing VS Code from recognizing the device.

Einar Thorsrud — Thu, 11 Dec 2025 10:26:53 GMT

Thank you, Zero. It looks like this may be caused by a bug in nrfutil, but we are still working on narrowing it down.

Are you running in a virtual machine (VM)? Also, are there any other factors about your environment that is worth mentioning?

RE: nrfutil cannot recognize J-Link, preventing flashing with nrfutil and preventing VS Code from recognizing the device.

zero — Thu, 11 Dec 2025 02:07:25 GMT

Hi，

As shown in the attachment, the file can be obtained by unzipping it.

devzone.nordicsemi.com/.../3716.logs.zip

BR,

Zero

RE: nrfutil cannot recognize J-Link, preventing flashing with nrfutil and preventing VS Code from recognizing the device.

Einar Thorsrud — Tue, 09 Dec 2025 09:50:45 GMT

Hi Zero,

Thank you. However, it does not seem to be the right log file. It looks like you are running nrfutil from a nRF Connect SDK toolchain? If so, the path is different. Can you try to run the command "nrfutil device list --log-level trace" again and see if there is a log file at D:/ncs/toolchains/c1a76fddb2/nrfutil/home/logs/nrfutil-device.log ? If so, can you share that? If not, an option could be if you can install nrfutil outside of the toolchain and run it there, and use the path I referred to in my previous post?

RE: nrfutil cannot recognize J-Link, preventing flashing with nrfutil and preventing VS Code from recognizing the device.

zero — Tue, 09 Dec 2025 02:13:17 GMT

Hi，

[quote userid="7377" url="~/f/nordic-q-a/126003/nrfutil-cannot-recognize-j-link-preventing-flashing-with-nrfutil-and-preventing-vs-code-from-recognizing-the-device/556440"]If that does not work, can you share a screenshot from the Board configurator as well so that I see the configuration?[/quote]

[quote userid="7377" url="~/f/nordic-q-a/126003/nrfutil-cannot-recognize-j-link-preventing-flashing-with-nrfutil-and-preventing-vs-code-from-recognizing-the-device/556440"]And lastly, can you let me know if you have a DK or PDK, and the version that is printed on it? (A photo of the DK would also give this information).[/quote]

[quote userid="7377" url="~/f/nordic-q-a/126003/nrfutil-cannot-recognize-j-link-preventing-flashing-with-nrfutil-and-preventing-vs-code-from-recognizing-the-device/556440"]Edit: can you also run "nrfutil device list --log-level trace" and upload the log from C:\Users\<USER>\.nrfutil\logs\nrfutil-device.log here? (Replace <USER> with your username on the local machine[/quote]

devzone.nordicsemi.com/.../5353.nrfutil_2D00_device.log

BR,

Zero

RE: nrfutil cannot recognize J-Link, preventing flashing with nrfutil and preventing VS Code from recognizing the device.

Einar Thorsrud — Mon, 08 Dec 2025 11:26:12 GMT

Hi,

I see, this does not look correct. Can you use the Board configurator and make sure SWD is enabled on the DK?

If that does not work, can you share a screenshot from the Board configurator as well so that I see the configuration? And lastly, can you let me know if you have a DK or PDK, and the version that is printed on it? (A photo of the DK would also give this information).

Edit: can you also run "nrfutil device list --log-level trace" and upload the log from C:\Users\<USER>\.nrfutil\logs\nrfutil-device.log here? (Replace <USER> with your username on the local machine).

RE: nrfutil cannot recognize J-Link, preventing flashing with nrfutil and preventing VS Code from recognizing the device.

zero — Mon, 08 Dec 2025 08:09:23 GMT

Hi，

[quote userid="7377" url="~/f/nordic-q-a/126003/nrfutil-cannot-recognize-j-link-preventing-flashing-with-nrfutil-and-preventing-vs-code-from-recognizing-the-device/556324"]If you do not see ny device then, can you check with a different USB cable in case there is a problem with the cable? Also please verify that the on/off switch on the DK is so that it is on, and that you see an active LED on the DK (the LED for the onboard debugger).[/quote]

I have already replaced the USB cable with one that is known to be working, and I have also confirmed that the development board is receiving power properly.

BR,

Zero

RE: nrfutil cannot recognize J-Link, preventing flashing with nrfutil and preventing VS Code from recognizing the device.

Einar Thorsrud — Fri, 05 Dec 2025 12:32:46 GMT

Hi Zero,

I see from the log that one J-Link device is found. Can you run the command "nrfutil device list" and share the result here? If you do not see ny device then, can you check with a different USB cable in case there is a problem with the cable? Also please verify that the on/off switch on the DK is so that it is on, and that you see an active LED on the DK (the LED for the onboard debugger).