Error with CharacterMotor and unpausing

I'm currently using the CharacterMotor script, to control movement and if I pause and then unpause while moving forward or jumping it results in either the character falling really fast or worse:

transform.positionWithLocalOffset > assign attempt for 'Player' is not > valid. Input positionWithLocalOffset > is { NaN, -28.434168, NaN }.

The script gets disabled on pause and then re-enabled on resume via my pause script which is:

 void Awake() {
 player = GameObject.FindWithTag ("Player").GetComponent<CharacterMotor> ();
     playerController = GameObject.FindWithTag("Player").GetComponent<CharacterController();
 }
             void PauseGame() {
                 isPause = !isPause;
                 if(isPause){
                     player.enabled = false;
                     playerController.enabled = false;
                     Time.timeScale = 0;
         
                 }
                 else{
                     Time.timeScale = 1;
                     player.enabled = true;
                     playerController.enabled = true;
                 }
             }    
 

I've checked and they definitely get disabled and re-enabled. I'm assuming it is coming from the way CharacterMotor calculates velocity:

 movement.velocity = (tr.position - lastPosition) / Time.deltaTime;

which must be then trying to divide by zero. What can I do to avoid this problem?

edit: for now i have set Time.timeScale = 0.001; which seems to work is there a better way to tackle this problem, or will this be fine?

Thanks,

Dan