UART BLE connection while saving data inside FLASH

Question

Hi all, 
 I am working on a new project and I need to communicate to a sensor using I2C, then save the data on a flash (files visible on windows as mass storage via USB) and also sending UART data via BLE. 
 I modified the USBD_MSC SDK example to acquire the data and save them on the flash and make the files visible from windows via USB and it works as expected. 
 Then I modified the ble_app_uart SDK example (peripheral one) to acquire the data and send it via BT UART and it works as expected. 
 Now I am trying to merge the two modified working examples to have all the functionalities but the debugger stops during the uart_init() and log_init() functions with error. 
 I think that it is because first I initialize the UART to work with USB and then I try to initialize it a second time for BLE communication. 
 What is the right way to initialize all functionalities to implement both USB and BLE communication? 
 Following the merged code. 
 int main(void)
{
 ret_code_t err_code;
 ret_code_t ret;

 static const app_usbd_config_t usbd_config = {
 .ev_state_proc = usbd_user_ev_handler
 };

 ret = NRF_LOG_INIT(app_usbd_sof_timestamp_get);
 APP_ERROR_CHECK(ret);
 NRF_LOG_DEFAULT_BACKENDS_INIT();

 ret = nrf_drv_clock_init();
 APP_ERROR_CHECK(ret);

 nrf_drv_clock_lfclk_request(NULL);
 
 while(!nrf_drv_clock_lfclk_is_running())
 {
 /* Just waiting */
 }

 nrf_delay_ms(500);

 ret = app_timer_init();
 APP_ERROR_CHECK(ret);

 fatfs_init();

 ret = app_usbd_init(&usbd_config);
 APP_ERROR_CHECK(ret);

 app_usbd_class_inst_t const * class_inst_msc = app_usbd_msc_class_inst_get(&m_app_msc);
 ret = app_usbd_class_append(class_inst_msc);
 APP_ERROR_CHECK(ret);

 NRF_LOG_INFO("USBD MSC example started.");

 ret = app_usbd_power_events_enable();
 APP_ERROR_CHECK(ret);

 twi_init();
 nrf_delay_ms(500);

 // Initialize.
 uart_init();
 log_init();
 timers_init();
 power_management_init();
 ble_stack_init();
 gap_params_init();
 gatt_init();
 services_init();
 advertising_init();
 conn_params_init();

 // Start execution.
 advertising_start(); 
 
 Thank you very much. 
 
 Best regards.

Luca