diff --git a/Unity.Entities.Hybrid.Tests/DefaultWorldInitializationTests.cs b/Unity.Entities.Hybrid.Tests/DefaultWorldInitializationTests.cs
new file mode 100644
index 00000000..520dca66
--- /dev/null
+++ b/Unity.Entities.Hybrid.Tests/DefaultWorldInitializationTests.cs
@@ -0,0 +1,37 @@
+using System;
+using System.Collections;
+using NUnit.Framework;
+using UnityEditor;
+using UnityEditor.TestTools;
+using UnityEngine;
+using UnityEngine.TestTools;
+
+namespace Unity.Entities.Tests
+{
+    public class DefaultWorldInitializationTests
+    {
+        
+        [SetUp]
+        public void Setup()
+        {
+        }
+// TODO: [case 1040539] Remove this when entering playmode in an editmode test works in 2018.2+
+#if UNITY_2018_1_OR_NEWER && !UNITY_2018_2_OR_NEWER
+        [UnityTest]
+        public IEnumerator Initialize_WhenEnteringPlaymode_ShouldLogNothing()
+        {
+            EditorApplication.isPlaying = true;
+            yield return null;
+        
+            
+            LogAssert.NoUnexpectedReceived();
+        }
+#endif
+        [TearDown]
+        public void TearDown()
+        {
+            EditorApplication.isPlaying = false;
+
+        }
+    }
+}
diff --git a/Unity.Entities.Hybrid.Tests/DefaultWorldInitializationTests.cs.meta b/Unity.Entities.Hybrid.Tests/DefaultWorldInitializationTests.cs.meta
new file mode 100644
index 00000000..ac3862f2
--- /dev/null
+++ b/Unity.Entities.Hybrid.Tests/DefaultWorldInitializationTests.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: e56cae007ac8d4879b5459a5bde872dc
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Unity.Entities.Hybrid/Injection/DefaultWorldInitialization.cs b/Unity.Entities.Hybrid/Injection/DefaultWorldInitialization.cs
index 244bf47d..1d653c91 100644
--- a/Unity.Entities.Hybrid/Injection/DefaultWorldInitialization.cs
+++ b/Unity.Entities.Hybrid/Injection/DefaultWorldInitialization.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
 using UnityEngine;
@@ -37,54 +38,75 @@ public static void Initialize(string worldName, bool editorWorld)
 
             PlayerLoopManager.RegisterDomainUnload(DomainUnloadShutdown, 10000);
 
+            IEnumerable<Type> allTypes;
+
             foreach (var ass in AppDomain.CurrentDomain.GetAssemblies())
             {
                 try
                 {
-                    var allTypes = ass.GetTypes();
-
-                    // Create all ComponentSyste
-                    var systemTypes = allTypes.Where(t =>
-                        t.IsSubclassOf(typeof(ComponentSystemBase)) &&
-                        !t.IsAbstract &&
-                        !t.ContainsGenericParameters &&
-                        (t.GetCustomAttributes(typeof(ComponentSystemPatchAttribute), true).Length == 0) &&
-                        t.GetCustomAttributes(typeof(DisableAutoCreationAttribute), true).Length == 0);
-                    foreach (var type in systemTypes)
-                    {
-                        if (editorWorld && type.GetCustomAttributes(typeof(ExecuteInEditMode), true).Length == 0)
-                            continue;
-
-                        GetBehaviourManagerAndLogException(world, type);
-                    }
+                    allTypes = ass.GetTypes();
+
                 }
-                catch (ReflectionTypeLoadException)
+                catch (ReflectionTypeLoadException e)
                 {
-                    // Can happen for certain assembly during the GetTypes() step
+                    allTypes = e.Types.Where(t => t != null);
+                    Debug.LogWarning("DefaultWorldInitialization failed loading assembly: " + ass.Location);
                 }
+
+                // Create all ComponentSystem
+                CreateBehaviourManagersForMatchingTypes(editorWorld, allTypes, world);
             }
-            
+
             foreach (var ass in AppDomain.CurrentDomain.GetAssemblies())
             {
-                var allTypes = ass.GetTypes();
-
-                // Create all ComponentSystem
-                var systemTypes = allTypes.Where(t => 
-                    t.IsSubclassOf(typeof(ComponentSystemBase)) && 
-                    !t.IsAbstract && 
-                    !t.ContainsGenericParameters && 
-                    (t.GetCustomAttributes(typeof(ComponentSystemPatchAttribute), true).Length > 0) &&
-                    t.GetCustomAttributes(typeof(DisableAutoCreationAttribute), true).Length == 0);
-                foreach (var type in systemTypes)
+                try
                 {
-                    if (editorWorld && type.GetCustomAttributes(typeof(ExecuteInEditMode), true).Length == 0)
-                        continue;
-
-                    world.AddComponentSystemPatch(type);
+                    allTypes = ass.GetTypes();
                 }
+                catch (ReflectionTypeLoadException e)
+                {
+                    allTypes = e.Types.Where(t => t != null);
+                    Debug.LogWarning("DefaultWorldInitialization failed loading assembly: " + ass.Location);
+                }
+
+                AddComponentSystemPatchesForMatchingTypes(editorWorld, allTypes, world);
             }
 
             ScriptBehaviourUpdateOrder.UpdatePlayerLoop(world);
         }
+
+        static void CreateBehaviourManagersForMatchingTypes(bool editorWorld, IEnumerable<Type> allTypes, World world)
+        {
+            var systemTypes = allTypes.Where(t =>
+                t.IsSubclassOf(typeof(ComponentSystemBase)) &&
+                !t.IsAbstract &&
+                !t.ContainsGenericParameters &&
+                t.GetCustomAttributes(typeof(ComponentSystemPatchAttribute), true).Length == 0 &&
+                t.GetCustomAttributes(typeof(DisableAutoCreationAttribute), true).Length == 0);
+            foreach (var type in systemTypes)
+            {
+                if (editorWorld && type.GetCustomAttributes(typeof(ExecuteInEditMode), true).Length == 0)
+                    continue;
+
+                GetBehaviourManagerAndLogException(world, type);
+            }
+        }
+
+        static void AddComponentSystemPatchesForMatchingTypes(bool editorWorld, IEnumerable<Type> allTypes, World world)
+        {
+            var systemTypes = allTypes.Where(t =>
+                t.IsSubclassOf(typeof(ComponentSystemBase)) &&
+                !t.IsAbstract &&
+                !t.ContainsGenericParameters &&
+                t.GetCustomAttributes(typeof(ComponentSystemPatchAttribute), true).Length > 0 &&
+                t.GetCustomAttributes(typeof(DisableAutoCreationAttribute), true).Length == 0);
+            foreach (var type in systemTypes)
+            {
+                if (editorWorld && type.GetCustomAttributes(typeof(ExecuteInEditMode), true).Length == 0)
+                    continue;
+
+                world.AddComponentSystemPatch(type);
+            }
+        }
     }
 }
diff --git a/Unity.Entities/Stubs/Unity/Debug.cs b/Unity.Entities/Stubs/Unity/Debug.cs
index e329d3bb..9145b0af 100644
--- a/Unity.Entities/Stubs/Unity/Debug.cs
+++ b/Unity.Entities/Stubs/Unity/Debug.cs
@@ -10,6 +10,11 @@ public static void LogError(object message)
             UnityEngine.Debug.LogError(message);
         }
 
+        public static void LogWarning(object message)
+        {
+            UnityEngine.Debug.LogWarning(message);
+        }
+
         public static void Log(object message)
         {
             UnityEngine.Debug.Log(message);
diff --git a/package.json b/package.json
index 5fded592..61c0a688 100644
--- a/package.json
+++ b/package.json
@@ -3,14 +3,14 @@
         "entities", 
         "unity"
     ], 
-    "version": "0.0.12-preview.2", 
+    "version": "0.0.12-preview.4", 
     "name": "com.unity.entities", 
     "dependencies": {
         "com.unity.collections": "0.0.9-preview.1", 
-        "com.unity.properties": "0.1.18-preview.2", 
-        "com.unity.burst": "0.2.4-preview.5", 
+        "com.unity.properties": "0.1.14-preview.2", 
+        "com.unity.burst": "0.2.4-preview.7", 
         "com.unity.jobs": "0.0.7-preview.1", 
-        "com.unity.mathematics": "0.0.12-preview.2"
+        "com.unity.mathematics": "0.0.12-preview.5"
     }, 
     "description": "Unity Entity Component System - Core Entity Component System, New Transform components, basic Instance Mesh Renderer"
 }
\ No newline at end of file