What is error code 0x00000004?

[MichaelNordicUser]

In my debugger, I see that variable error_code is 0x00000004

void app_error_handler_bare(ret_code_t error_code)
{
    error_info_t error_info =
    {
        .line_num    = 0,
        .p_file_name = NULL,
        .err_code    = error_code,
    };

    app_error_fault_handler(NRF_FAULT_ID_SDK_ERROR, 0, (uint32_t)(&error_info));

    UNUSED_VARIABLE(error_info);
}

Here is the call stack

What does this error code stand for?

edit

I see that this error stands for NRF_ERROR_NO_MEM and is the return value of softdevice_enable(&ram_start) called in ble_stack_init()