sd_ble_gatts_hvx and NRF_ERROR_SVC_HANDLER_MISSING

Question

Hello. 
 I try to periodically updated data in my characteristic that way: 
 uint32_t ble_first_service_send(uint16_t my_conn_handle, ble_my_service_t * p_my_service, ble_my_service_meas_t * p_my_service_meas) 
{
	uint8_t err_code;
 
	if(m_conn_handle != BLE_CONN_HANDLE_INVALID) 
	{	
 uint8_t encoded_sensor[MAX_SENSOR_LEN]; 
 uint16_t len;
 ble_gatts_hvx_params_t hvx_params;

 NRF_LOG_INFO("CONNECTION OK");
 
 len = my_service_measurement_encode(p_my_service, p_my_service_meas, encoded_sensor); 

 memset(&hvx_params, 0, sizeof(hvx_params));

 hvx_params.handle = p_my_service->first_char_handles.value_handle;
 hvx_params.type = BLE_GATT_HVX_NOTIFICATION;
 hvx_params.p_len = &len;
 hvx_params.p_data = encoded_sensor; 

 err_code = sd_ble_gatts_hvx(m_conn_handle, &hvx_params);
	}
	else
	{
 err_code = NRF_ERROR_INVALID_STATE;
	}
	return err_code;
} 
 As soon as I connected via "nRF Connect", function " sd_ble_gatts_hvx" returns: NRF_ERROR_SVC_HANDLER_MISSING. 
 The window looks like: 
 
 If I open the window: 
 
 functions "sd_ble_gatts_hvx" returns NRF_ERROR_INVALID_STATE, which without enabled notification is correct value. Does anyone know, what happen in app when I open this window? 
 Why functions returns NRF_ERROR_SVC_HANDLER_MISSING ? 
 Characteristic add function: 
 static uint32_t my_first_char_add(ble_my_service_t * p_my_service, const ble_my_service_init_t * p_my_service_init)
{
	ble_gatts_char_md_t char_md; 
	ble_gatts_attr_md_t cccd_md; 
	ble_gatts_attr_t attr_char_value; 
	ble_gatts_attr_md_t attr_md; 
	ble_uuid_t ble_uuid;
	ble_my_service_meas_t initial_bpm;
	uint8_t encoded_sensor[MAX_SENSOR_LEN];

	memset(&cccd_md, 0, sizeof(cccd_md));

	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.read_perm);
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.write_perm);
	cccd_md.vloc = BLE_GATTS_VLOC_STACK;

	memset(&char_md, 0, sizeof(char_md));

	char_md.char_props.read = 1;
	char_md.char_props.notify = 1;
	char_md.p_char_user_desc = NULL;
	char_md.p_char_pf = NULL;
	char_md.p_user_desc_md = NULL;
	char_md.p_cccd_md = &cccd_md;
	char_md.p_sccd_md = NULL;
	
	ble_uuid.type = p_my_service->uuid_type;
	ble_uuid.uuid = BLE_UUID_MY_SERVICE_CHAR_1; 
 
	memset(&attr_md, 0, sizeof(attr_md));
	
	BLE_GAP_CONN_SEC_MODE_SET_OPEN(&attr_md.read_perm);
	BLE_GAP_CONN_SEC_MODE_SET_NO_ACCESS(&attr_md.write_perm);

	attr_md.vloc = BLE_GATTS_VLOC_STACK;
	attr_md.rd_auth = 0;
	attr_md.wr_auth = 0;
	attr_md.vlen = 0;
 
	memset(&attr_char_value, 0, sizeof(attr_char_value));

	attr_char_value.p_uuid = &ble_uuid;
	attr_char_value.p_attr_md = &attr_md;
	attr_char_value.init_len = my_service_measurement_encode(p_my_service, &initial_bpm, encoded_sensor);
	attr_char_value.init_offs = 0;
	attr_char_value.max_len = MAX_SENSOR_LEN;
	attr_char_value.p_value = fake_data0;

 return sd_ble_gatts_characteristic_add(p_my_service->service_handle, &char_md, &attr_char_value, &p_my_service->first_char_handles);
} 
 
 Best regards 
 PW