Visual Studio Code: Unable to find worker executable / Unable to flash target

[radio200000]

Hi all

Coming back to an nrf52840 project after some weeks, VScode nRF extension do not work anymore.

Trying to recover a board (nRF52840DK) gives error:

08:52:50] nrfutil-device recover --serial-number 001050261677 --json
[08:52:51] Error: One or more recover tasks failed:
* 1050261677: Unable to find worker executable: Custom { kind: NotFound, error: "Failed to find file plugin-probe-worker. Looked for file in <none>, <none>, /home/vsts/.cargo/registry/src/eu.files.nordicsemi.com-aeee3781a8ecf169/target/release/plugin-probe-worker and /home/developer/.vscode/extensions/nordic-semiconductor.nrf-connect-2025.9.754-linux-x64/platform/nrfutil/bin/plugin-probe-worker" } (Generic)

Trying to flash a binary to the target gives error:

Executing task: nRF Connect: Flash: <project-directory><project-name> (active)

Flashing <project-name> to nRF52840 DK
west flash -d /home/developer/work/<project-directory>/build --domain <project-name> --dev-id 1050261677

-- west flash: rebuilding
[0/10] Performing build step for '<project-name>'
ninja: no work to do.
[1/10] Performing build step for 'mcuboot'
ninja: no work to do.
[4/10] cd /home/developer/work/<project-directory>/build/_sysbuild && /home/developer/ncs/tool[7/9] cd /home/developer/work/<project-directory>/build/_sysbuild && /home/developer/ncs/toolc[8/9] cd /home/developer/work/<project-directory>/build/_sysbuild && /home/developer/ncs/toolchains/7cbc0036f4/usr/local/bin/cmake -E true
-- west flash: using runner nrfutil
-- runners.nrfutil: reset after flashing requested
FATAL ERROR: required program nrfutil not found; install it or add its location to PATH

Validating the toolchain gives no errors:

[09:09:41] =========== Toolchain validation report for nRF Connect SDK Toolchain v3.0.2 ===========
Package Using the nRF Connect SDK v3.0.2 at /home/developer/ncs/v3.0.2
No issues were detected with the toolchain.

Versions:

Visual Studio Code: 1.104.0

nRF Connect for VS Code Extension Pack: 2025.4.4

nRF Connect for VS Code: 2025.9.754

nRF DeviceTree: 2025.8.140

nRF Kconfig: 2025.9.123

nRF Terminal: 2025.8.103

Any idea what's wrong here?

Thanks!

--

Kind regards

[Vidar Berg]

Hello,

[08:52:51] Error: One or more recover tasks failed:
* 1050261677: Unable to find worker executable: Custom { kind: NotFound, error: "Failed to find file plugin-probe-worker. Looked for file in <none>, <none>, /home/vsts/.cargo/registry/src/eu.files.nordicsemi.com-aeee3781a8ecf169/target/release/plugin-probe-worker and /home/developer/.vscode/extensions/nordic-semiconductor.nrf-connect-2025.9.754-linux-x64/platform/nrfutil/bin/plugin-probe-worker" } (Generic)

This is an unfortunate bug introduced in recent update of our VS code extension. We are planning to make a new release to address this soon. In the meantime if you need to recover a board, please use the "nrfutil device recover" from the command line instead.

FATAL ERROR: required program nrfutil not found; install it or add its location to PATH

This indicates that the nRF Util executable is not found on your system. It's not part of the toolchain and needs to be installed separately following the instructions here: https://docs.nordicsemi.com/bundle/nrfutil/page/guides/installing.html 

Kind regards,

Vidar

[radio200000]

Thanks for your reply.

Flashing the flash has worked before with my setup. So I guess it should still work even after an update of the extension.

I found nrfutil in /home/developer/.config/nrfconnect/nrfutil-sandboxes/toolchain-manager/0.15.0/bin/nrfutil

Is there something else that changed?

Regards

[Vidar Berg]

I think we've been unlucky to have hit several seemingly unrelated issues. The latter appears more like a connectivity issue with your DK. Which version of Jlink is listed when you run nrfutil device --version?

[radio200000]

~/bin$ nrfutil device --version
nrfutil-device 2.14.0 (fc03a3f 2025-09-16)
commit-hash: fc03a3f4e33bdcc94452363f8b42a464de48166a
commit-date: 2025-09-16
host: x86_64-unknown-linux-gnu
build-timestamp: 2025-09-16T10:17:08.723659415Z
classification: nrf-external

Detected SEGGER J-Link version: JLink_V8.18

The device command version you are currently using was tested with a different J-Link version (JLink_V8.60) than the one you have installed (JLink_V8.18). The tested version is not required, and your J-Link version will most likely work fine. If you get issues related to J-Link with your devices, use the tested version.

[Vidar Berg]

Please run the 'JLinkConfig' executable and check if there are any updates available for the J-link OB FW on the DK. It might also be worth upgrading the Jlnk v.8.60 as the text suggests, but I'm not convinced it would make any difference. 

[radio200000]

Just about an hour ago I started JLinkExe and it instructed me to update the firmware on the debugger. This solved the problem of not being able to flash (and also board recovery via CLI) works now.

Extension is still broken though.

[Vidar Berg]

That's one problem solved, at least. Regarding the issue with the extension, could you please double check the the extension got updated to 2025.9.798 and that it's not on 2025.9.789 still? This release did fix the issue on my end so I don't understand why it did not fix it in your case.

[radio200000]

Version just got updated to 2025.9.798. Recovery is now working again.

Many thanks for your support!