< "A" fatal error occurs while processing MTU extension. 
  "A" sdk12.3 52832 Peripheral function
  "B" sdk15.2 52832 Central function >
  
0> APP:INFO:Start scanning for device name Cretam_Safety.
 0> APP:INFO:Fast Advertising
 0> APP:INFO:Multilink Example
 0> APP:INFO:Peripheral connected
 0> BLE_GATT:INFO:on_connected_evt(nrf_ble_gatt_t * p_gatt, ble_evt_t * p_ble_evt)
 0> BLE_GATT:INFO:request ATT MTU 64 for conn_handle 0 
 0> SDH:DEBUG:sd_ble_enable: RAM start at 0x200056a8
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< "A" sdk12.3 52832 Peripheral function
  "B" nRFTool -> UART on smartphone >
  
0> APP:INFO:Peripheral connected
 0> BLE_GATT:INFO:on_connected_evt(nrf_ble_gatt_t * p_gatt, ble_evt_t * p_ble_evt)
 0> BLE_GATT:INFO:request ATT MTU 64 for conn_handle 0 
 0> BLE_GATT:INFO:EXCHANGE_MTU_RSP effective ATT MTU is 64 for conn_handle 0 
 0> APP:DEBUG:ATT MTU exchange completed. central 0xf7 peripheral 0x40
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