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,

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

[Ben_M]

Hi Abhijith,

Sorry for the late reply—I was tied up with other work.

Menon said:

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.

I have tested the Peripheral UART example on my custom development board and did not observe any reset errors.
Does this mean the device tree configuration for my custom board is correct, and that the issue might instead lie in the code or in other communication processes between the Netcore and the Appcore?

Menon said:

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

The build folder does contain two images. To prevent problems when flashing the application or network cores, I checked before every build-and-flash in my earlier tests to ensure that the full and correct images were flashed.

Hope you can give me more clues.

Best Regards!

Ben