Caching.ready

Возвращает true, если система Кэширования готова к использованию.

using System.Collections;
using UnityEngine;
using UnityEngine.Networking;

public class Example : MonoBehaviour
{
    IEnumerator IsCachingReadyExample(string uri)
    {
        //Using this conditional says we want to wait for our Caching system to be ready before trying to download bundles
        while (!Caching.ready)
        {
            yield return null;
        }
        //Download the bundle
        UnityWebRequest request = UnityWebRequestAssetBundle.GetAssetBundle(uri);
        yield return request.SendWebRequest();
        AssetBundle bundle = DownloadHandlerAssetBundle.GetContent(request);

        //Do something with the AssetBundle...

        //Unload the AssetBundle
        bundle.Unload(true);
    }
}