Bluetooth init fails with error -11 after reset on nRF5340 (NCS v2.9.0)

[Ben_M]

Hi Nordic，

I encountered a strange issue when compiling and flashing my nRF5340 project with NCS v2.9.0.

• On the first flash, everything works fine. Bluetooth starts successfully.

• After I use VS Code "Reset" (without reflashing), the system reboots, but Bluetooth initialization fails with error -11.

Here are the logs for comparison:

First boot (works fine):

*** Booting nRF Connect SDK v2.9.0-7787b2649840 ***
*** Using Zephyr OS v3.7.99-1f8f3dc29142 ***
[00:00:01.415,557] <inf> usb_cdc_acm: Device suspended
[00:00:01.431,976] <inf> ADS1299_log: ADS1299 init success  62
[00:00:01.451,660] <inf> bt_hci_core: HW Platform: Nordic Semiconductor (0x0002)
[00:00:01.451,690] <inf> bt_hci_core: HW Variant: nRF53x (0x0003)
[00:00:01.451,721] <inf> bt_hci_core: Firmware: Standard Bluetooth controller (0x00) Version 45.41337 Build 3074452168
[00:00:01.487,152] <inf> bt_hci_core: No ID address. App must call settings_load()
[00:00:01.488,403] <inf> bt_hci_core: Identity: DA:97:F9:91:41:A4 (random)
[00:00:01.488,433] <inf> bt_hci_core: HCI: version 6.0 (0x0e) revision 0x206b, manufacturer 0x0059
[00:00:01.488,464] <inf> bt_hci_core: LMP: version 6.0 (0x0e) subver 0x206b
[00:00:01.488,525] <err> bt_gatt: Failed to save Database Hash (err -2)
[00:00:01.488,800] <inf> main_thread_log: BT addr: DA:97:F9:91:41:A4

Second boot (after reset, Bluetooth fails):

*** Booting nRF Connect SDK v2.9.0-7787b2649840 ***
*** Using Zephyr OS v3.7.99-1f8f3dc29142 ***
[00:00:01.511,138] <inf> usb_cdc_acm: Device suspended
[00:00:01.527,557] <inf> ADS1299_log: ADS1299 init success  62
[00:00:02.530,303] <err> bt_hci_driver: Endpoint binding failed with -11
[00:00:02.530,334] <err> bt_hci_core: HCI driver open failed (-11)
[00:00:02.530,364] <err> main_thread_log: Bluetooth init failed (err -11)

My questions:

1. Why does Bluetooth initialization succeed after the first flash but fail with -11 after a reset? Is there any additional configuration required for reset handling on nRF5340?

2. During the first boot, I also see:

   <err> bt_gatt: Failed to save Database Hash (err -2)

   What exactly does error -2 mean here? I have read in forum posts that this error might not affect usage — is this still the case with NCS v2.9.0, or should I configure settings/NVS properly to avoid it.

Thank you for your support!

Best Regards!

Ben

[Menon]

Hello Ben,

Sorry, but I need a bit more time to look into this issue. You can expect a response by the end of Monday next week. I apologize for any inconvenience this may cause.

Kind regards,
Abhijith

[Menon]

Hello,

I noticed a similar issue reported in this DevZone case. From the error logs, it looks like the net core image (bt_hci_ipc) isn’t running or matching the host’s expectations. Do you have SB_CONFIG_NETCORE_HCI_IPC enabled in your sysbuild.conf, see migration notes?

Since you are migrating from NCS v2.6.x to NCS v2.9.x, you are moving from a multi-image build to Sysbuild. I recommend following the migration guide.

Could you also check if this issue is related to nrfutil? Try updating nrfutil to the latest version and see if that resolves the problem.

Kind regards,
Abhijith

[Ben_M]

Hi Menon,

Thanks for your reply!

Menon said:

I noticed a similar issue reported in this DevZone case. From the error logs, it looks like the net core image (bt_hci_ipc) isn’t running or matching the host’s expectations. Do you have SB_CONFIG_NETCORE_HCI_IPC enabled in your sysbuild.conf, see migration notes?

Yes, I have enabled CONFIG option in "Kconfig.sysbuild" as follow. 

source "${ZEPHYR_BASE}/share/sysbuild/Kconfig"

config NRF_DEFAULT_IPC_RADIO
	default y

config NETCORE_IPC_RADIO_BT_HCI_IPC
	default y

I saw that there are two ways to enable netcore on the webpage: one is through Kconfig and the other is through Sysbuild. I also tried Sysbuild, but the issue was not resolved. I’m not sure if my understanding is correct?

I doucle check the Migration guide from v2.6.0 to v2.7.0, but the only configuration related to my application is FEM, and the other functions are not used. So far, FEM seems to be working properly, and the RSSI values are also normal.

Menon said:

Could you also check if this issue is related to nrfutil? Try updating nrfutil to the latest version and see if that resolves the problem.

current version is v8.0.0, and it doesn't resolve it after update to 8.1.1 

nrfutil 8.0.0 (54d8087 2025-01-07)
commit-hash: 54d8087a38b73b6e56942fb1b024b62365f06731
commit-date: 2025-01-07
host: x86_64-pc-windows-msvc
build-timestamp: 2025-01-07T14:31:30.208979700Z
classification: nrf-external

 

nrfutil 8.1.1 (b6089d0 2025-08-21)
commit-hash: b6089d08a9cfdb292f8ab8d21e0908ded814cd11
commit-date: 2025-08-21
host: x86_64-pc-windows-msvc
build-timestamp: 2025-08-21T14:12:43.593658000Z
classification: nrf-external

I hope you can provide further suggestions.

Best Regards!

Ben

[Ben_M]

Add Update on Issue 2 (SPI communication with ADS1299):

I found the data lines show square waves, but the SCLK looks a little bit rounded(yellow for sclk, green for miso). Is this normal? I also observed the same waveform on 2.6.0. Will this cause any problems?

[Menon]

Hello,

Could you try running a BLE sample from the SDK to see if the same issue persists? I suspect the problem might be due to the netcore image not being created correctly.

Also, please check if the generated build folder actually contains the CPUNET image.

Kind regards,
Abhijith