title: Unity ECS doesn't show created entites since package Update
body: <p>I tried to spawn some entities and assign a mesh and material to them. Somehow they do not appear, neither in the Editor nor the gameview. When I use a "GameObjectToEntity" Conversion Script the Entity does appear, I tried the new Alpha Version of the Editor (2020.1.0a25)  but it didnt help. I'm also using the URP. It might be connected to the updating the preview packagets (Entities, Hybrid Render etc.) since I don't have the problem in a different project where I'm using older versions.
  I might have missed something in my Code though.</p>
  
  <pre><code>using System.Collections;
  using System.Collections.Generic;
  using UnityEngine;
  using Unity.Entities;
  using Unity.Rendering;
  using Unity.Transforms;
  using Unity.Mathematics;
  using Unity.Collections;
  
  public class EntityCreator : MonoBehaviour
  {
  
      [SerializeField] public Mesh theMesh;
      [SerializeField] public Material theMaterial;
  
      // Start is called before the first frame update
      void Start()
      {
          EntityManager entityManager = World.DefaultGameObjectInjectionWorld.EntityManager;
  
          EntityArchetype eArch =  entityManager.CreateArchetype(
                  typeof(RenderMesh),
                  typeof(Translation),
                  typeof(LocalToWorld),
                  typeof(MoveSpeedComponent)
              );
  
          NativeArray&lt;Entity&gt; eArray = new NativeArray&lt;Entity&gt;(10, Allocator.Temp);
  
          entityManager.CreateEntity(eArch, eArray);
  
          foreach (Entity ent in eArray)
          {
              entityManager.SetComponentData(ent, new Translation { Value = new Vector3(0f,0f, 0f) });
              entityManager.SetSharedComponentData(ent, new RenderMesh 
              {
                  mesh = theMesh, material = theMaterial
              });
          }
          eArray.Dispose();
      }
  
  }
  </code></pre>
  
  <p>Thanks a lot for taking the time </p>