Error using Vehicle Can Bus Monitor app!!!!

Hello all, I get this eroor when I run Vehicle CAN Bus Monitor app:

Error using can.ni.xnet.NIXNET.checkStatus (line 141)
National Instruments NI-XNET function nxSetProperty returned error code BFF6311E indicating:

NI-XNET:  (Hex 0xBFF6311E) You attempted to perform an action on a session or interface that is started, and the action that requires the
session/interface to be stopped. Solution: Stop the object before performing this action.

Error in can.ni.xnet.NIXNET.nxSetProperty (line 87)
        can.ni.xnet.NIXNET.checkStatus(status, 'nxSetProperty');

Error in can.ni.xnet.Channel (line 158)
            NIXNET.nxSetProperty(obj.SessionReferenceInput, Utility.nxPropSession_IntfBaudRate, Utility.DefaultBusSpeed);

Error in canChannel (line 73)
        channel = can.ni.xnet.Channel(varargin{:});

Error in can.Tool/start (line 896)
                    obj.Channel = canChannel(currCh.Vendor, currCh.Device);

Error in can.Tool>@(varargin)obj.start(varargin{:}) (line 275)
            'ClickedCallback', @obj.start);
 
Error while evaluating PushTool ClickedCallback.

The code I am using is as follow:

clc
clear all
BusSpeed=50000;

%canHWInfo
rxCh = canChannel('NI','CAN1');                             %Create a Receiving Channel
txCh = canChannel('NI','CAN2');                             %Create a Transmiting Channel
configBusSpeed(rxCh,BusSpeed)
configBusSpeed(txCh,BusSpeed)


% canMessage %
messageout = canMessage(3333,true,5)

% Pack a Message %
pack(messageout,10,0,16,'LittleEndian')
messageout.Data

% Start channels %
start(rxCh)
start(txCh)

% Transmit a Message %
%transmit(txCh,messageout)
transmitPeriodic(txCh,messageout,'On',1);
%transmitConfiguration(txCh)
txCh
rxCh

I did try to run it before and after running the code but keep getting this massage!! Any idea?