NullReference

Here is my code

 using UnityEngine;
 using System.Collections;
 
 public class SolarSystemCreate : Photon.MonoBehaviour {
     public GameObject GasGiants;
     public GameObject Planets;
     float PlanetX;
     float PlanetY;
     float PlanetZ;
     float GasGiantX;
     float GasGiantY;
     float GasGiantZ;
     int PlanetCount;
     int GasGiantCount;
     int IsGasGiant;
     int IsPlanet;
     // Use this for initialization
     void Start () {
         IsGasGiant = Random.Range (1,30);
         IsPlanet = Random.Range (1,10);
         PlanetCount = Random.Range (1,20);
         GasGiantCount = Random.Range (1,3);
         int i = 0;
         int h = 0;
         // If IsPlanet is equal to 1 spawn planets
         if(IsPlanet == 1){
         while (i < PlanetCount) {
                         PlanetX = transform.position.x + Random.Range (-20384, 20384);
                         PlanetY = transform.position.y + Random.Range (-30, 30);
                         PlanetZ = transform.position.z + Random.Range (-20384, 20384);
                         GetComponent<PhotonView> ().RPC ("PlanetCreate",PhotonTargets.All);
                         i++;
                 }
         }
         //If IsGasGiant is equal to 1 spawn GasGiants
         if (IsGasGiant == 1) {
             while(h < GasGiantCount){
                 GasGiantX = transform.position.x + Random.Range (-20384, 20384);
                 GasGiantY = transform.position.y + Random.Range (-30, 30);
                 GasGiantZ = transform.position.z + Random.Range (-20384, 20384);
                 GetComponent<PhotonView> ().RPC ("GasGiantCreate",PhotonTargets.All);
                 h++;
             }
         }
         //fin
     }
     
     // Update is called once per frame
     void Update () {
     
     }
     [RPC]
     public void PlanetCreate () {
         Instantiate(Planets, new Vector3 (PlanetX, PlanetY, PlanetZ), Quaternion.identity);
     }
     [RPC]
     public void GasGiantCreate (){
         Instantiate (GasGiants, new Vector3 (GasGiantX, GasGiantY, GasGiantZ), Quaternion.identity);
     }
 }

What is suppose to happen is that it spawns in the planets and gas giants if the int GasgiantCount and PlanetCount is equal to one. But when it is equal to one it gives the error: NullReferenceException: Object reference not set to an instance of an object SolarSystemCreate.Start() (at Assets/Engine/SolarStstem/SolarSystemCreate.cs:31) I read that NullReferenceException is usually when something is getting a null (or nothing) and it needs a alternative code for when it does. But how can I get a alternative null code? By the way the errors are on line 31 and 41. Thanks for the help!