Updating then calling gameObject from main thread. error

 So I have a var name = gameObject; in the main thread, which is set 

``by a raycast hit, so name = hit.transform.gameObject; but it seems that it isn't updating the var, and the ai just resets to o,o,o vector and it gives me this error/message

Look rotation viewing vector is zero UnityEngine.Quaternion:LookRotation(Vector3) lookatnew:AIStart() (at Assets/game/scripts/ai/enamie/basic/lookatnew.js:46)

what it is talking about.

 }
 else if (Aware && secondsSaved <= EndTime )
 {
     secondsSaved = seconds;
     EndTime = Timer + SetEndTime;

46 var rotationFallow = Quaternion.LookRotation(LastSaw.transform.position - transform.position);

     transform.rotation = Quaternion.Slerp(transform.rotation, rotationFallow, Time.deltaTime * Damping);
 }

which LastSaw is the var.

the function is a InvokeRepeating started randomly, buecuase this is a simple look at and find ai, so could that be the problem that it isn't updating it? which here is how i start the InvokeRepeating;

InvokeRepeating("AIStart", Random.Range(0, 1.0), 0.01);

This hopefully is the last error on this code i am making, thanks for any help.