While loop Crash

using System.Collections; using System.Collections.Generic; using UnityEngine;

public class Spawner : MonoBehaviour {

 public Wave[] waves;
 public Vector3[] spawnPos;



 Wave currentWave;
 int currentWaveNumber;
 int waveSize;
 int i;
 int k;
 int p;



 int [] enemiesRemainingToSpawn = new int[20];
 int enemiesRemainingAlive;
 float nextSpawnTime;



 void Start (){
     i = 0;
     k = 0;
     p = 0;
     waveSize = spawnPos.Length;
     NextWave ();
     StartCoroutine (SpawnEnemies ());

 }

 voidUpdate(){
     
 
 }

 IEnumerator SpawnEnemies(){

     while ( i <= currentWave.enemyType.Length){

         while (k <= currentWave.enemyCount[i]  ){

             if (enemiesRemainingToSpawn[i] > 0 ) {    
                 enemiesRemainingToSpawn[i]--;
                 nextSpawnTime = currentWave.timeBeetweenSpawns;

                 LivingEntities spawnedEnemy = Instantiate (currentWave.enemyType [i], spawnPos [Random.Range (0, waveSize)], Quaternion.identity) as LivingEntities;
                 spawnedEnemy.OnDeath += OnEnemyDeath;
                 k++;
                 yield return new WaitForSeconds (nextSpawnTime);
             
             }


         }

         i++;
     }

 
 
 }

 void NextWave() {
     currentWaveNumber++;
     if (currentWaveNumber - 1 < waves.Length){
     currentWave = waves [currentWaveNumber - 1];

         while (p <= currentWave.enemyCount.Length - 1){

             enemiesRemainingToSpawn[p] = currentWave.enemyCount[p];
             print("1");
             enemiesRemainingAlive = enemiesRemainingAlive + enemiesRemainingToSpawn[p];
             p++;
         
         }
     }
     i = 0;
     k = 0;
     p = 0;
 }


 void OnEnemyDeath()
 {
     enemiesRemainingAlive--;

     if (enemiesRemainingAlive == 0) {
         NextWave ();
     }
 }

 [System.Serializable]
 public class Wave {
     public int[] enemyCount;
     public float timeBeetweenSpawns;
     public LivingEntities[] enemyType;
 }

}

the SpawnEnemies Coroutine is the one that has a problem, could someone please help? I don't know why it isnt working.