WebGL abort at null function when using ECS

Hey, I'm doing some tests with ECS and WebGL and keep getting an error on startup.

Trace from a development build:

There's an error message included as well:

Here is the only script in the project:

Spoiler: Script

Code (CSharp):

1. using Unity.Entities;
2. using Unity.Mathematics;
3. using UnityEngine;
4.  
5. public struct CustomComp : IComponentData
6. {
7.     public float3 data;
8. }
9.  
10. public class TestSystem : ComponentSystem
11. {
12.     protected override void OnUpdate()
13.     {
14.         Entities.ForEach((ref CustomComp comp) =>
15.         {
16.             comp.data += 1;
17.         });
18.     }
19. }
20.  
21. public class ECSTest : MonoBehaviour
22. {
23.     // Start is called before the first frame update
24.     void Start()
25.     {
26.         EntityManager em = World.Active.EntityManager;
27.         EntityArchetype zombArch = em.CreateArchetype(
28.             typeof(CustomComp)
29.         );
30.  
31.         for (int i = 0; i < 10000; i++)
32.             CreateZombie(em, zombArch);
33.     }
34.  
35.     void CreateZombie(EntityManager em, EntityArchetype archetype)
36.     {
37.         Entity ent = em.CreateEntity(archetype);
38.  
39.         em.SetComponentData(ent, new CustomComp
40.         {
41.             data = new float3(0,0,0)
42.         });
43.     }
44. }

I'm using 2019.2.16f1. Any ideas? Thanks!