If tou have newver version of Unity, you might have trouble with not parallel showing up enemies. To fix that bug there is a simple solution:
From function SpawnAllWaves() remove statement “yield return” and after “for” loop add “return null;” statement.
for example:
- yield return StartCoroutine(SpawnAllEnemiesInWave(currentWave)); → remove “yield return”
- for (int WaveIndex = startingWaveIndex; WaveIndex < waveConfig.Count; WaveIndex++)
{
…
}
return null; ← here need to add this
Good luck Young Game Devs 
