RE: Erase mode.

Vidar Berg — Mon, 23 Mar 2026 14:00:36 GMT

Hello,

errata #36 Access port gets locked in WFI and WFE may prevent the read back protection from remaining unlocked if the device is allowed to enter the lowest power saving modes. But there was an update made to the nrfutil device command to help mitigate this problem.

(ref. https://docs.nordicsemi.com/bundle/nrfutil/page/nrfutil-device/CHANGELOG.html).

If you have not already done so, please try upgrading the nrfutil device version included in your toolchain (C:\ncs\toolchains\fd21892d0f). To do this, open a terminal with the toolchain environment configured, and run nrfutil upgrade to update the nrfutil device command for that toolchain version.

Disabling CONFIG_NRF_APPROTECT_USE_UICR will not help keeping the approtect mechanism disabled. For more details, please see https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/security/ap_protect.html

Best regards,

Vidar