diff --git a/Apps/Sandcastle/gallery/development/Circle Outline.html b/Apps/Sandcastle/gallery/development/Circle Outline.html
index 1b4b8197bf2c..1a86927228f6 100644
--- a/Apps/Sandcastle/gallery/development/Circle Outline.html	
+++ b/Apps/Sandcastle/gallery/development/Circle Outline.html	
@@ -42,7 +42,7 @@
 });
 // Add the geometry instance to primitives.
 scene.primitives.add(new Cesium.Primitive({
-    geometryInstances : [circleOutlineInstance],
+    geometryInstances : circleOutlineInstance,
     appearance : new Cesium.PerInstanceColorAppearance({
         flat : true,
         renderState : {
@@ -72,7 +72,7 @@
 });
 // Add the geometry instance to primitives.
 scene.primitives.add(new Cesium.Primitive({
-    geometryInstances : [circleOutlineInstance],
+    geometryInstances : circleOutlineInstance,
     appearance : new Cesium.PerInstanceColorAppearance({
         flat : true,
         renderState : {
diff --git a/Apps/Sandcastle/gallery/development/Circle.html b/Apps/Sandcastle/gallery/development/Circle.html
index 90ce6451ddbd..8249668fcada 100644
--- a/Apps/Sandcastle/gallery/development/Circle.html
+++ b/Apps/Sandcastle/gallery/development/Circle.html
@@ -45,7 +45,7 @@
 });
 // Add the geometry instance to primitives.
 scene.primitives.add(new Cesium.Primitive({
-    geometryInstances: [redCircleInstance],
+    geometryInstances: redCircleInstance,
     appearance: new Cesium.PerInstanceColorAppearance({
         closed: true
     })
@@ -71,7 +71,7 @@
 });
 // Add the geometry instance to primitives.
 scene.primitives.add(new Cesium.Primitive({
-    geometryInstances: [greenCircleInstance],
+    geometryInstances: greenCircleInstance,
     appearance: new Cesium.PerInstanceColorAppearance({
         closed: true
     })
diff --git a/Apps/Sandcastle/gallery/development/Corridor.html b/Apps/Sandcastle/gallery/development/Corridor.html
index ab28a0500387..7866eb4b355a 100644
--- a/Apps/Sandcastle/gallery/development/Corridor.html
+++ b/Apps/Sandcastle/gallery/development/Corridor.html
@@ -49,7 +49,7 @@
 });
 // Add the geometry instance to primitives.
 scene.primitives.add(new Cesium.Primitive({
-    geometryInstances : [redCorridorInstance],
+    geometryInstances : redCorridorInstance,
     appearance : new Cesium.PerInstanceColorAppearance({
         closed : true
     })
@@ -118,7 +118,7 @@
 });
 // Add the geometry instance to primitives.
 scene.primitives.add(new Cesium.Primitive({
-    geometryInstances : [blueCorridorInstance],
+    geometryInstances : blueCorridorInstance,
     appearance : new Cesium.PerInstanceColorAppearance({
         closed : true
     })
diff --git a/Apps/Sandcastle/gallery/development/Cylinder Outline.html b/Apps/Sandcastle/gallery/development/Cylinder Outline.html
index bdee996bacf6..98bb094eb184 100644
--- a/Apps/Sandcastle/gallery/development/Cylinder Outline.html	
+++ b/Apps/Sandcastle/gallery/development/Cylinder Outline.html	
@@ -55,7 +55,7 @@
 });
 // Add the instance to primitives.
 scene.primitives.add(new Cesium.Primitive({
-    geometryInstances : [cylinderOutline],
+    geometryInstances : cylinderOutline,
     appearance : new Cesium.PerInstanceColorAppearance({
         flat : true,
         renderState : {
diff --git a/CHANGES.md b/CHANGES.md
index c83cacff0d0b..888bf37ee814 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -42,7 +42,8 @@ Change Log
 * Fixed a bug where toggling point cloud classification visibility would result in a grey screen on Linux / Nvidia [#8538](https://github.com/AnalyticalGraphicsInc/cesium/pull/8538)
 * Fixed a bug where a point in a `PointPrimitiveCollection` is rendered in the middle of the screen instead of being clipped. [#8542](https://github.com/AnalyticalGraphicsInc/cesium/pull/8542)
 * Fixed a crash when deleting and re-creating polylines from CZML. `ReferenceProperty` now returns undefined when the target entity or property does not exist, instead of throwing. [#8544](https://github.com/AnalyticalGraphicsInc/cesium/pull/8544)
-* Fixed a bug where rapidly updating a PolylineCollection could result in an instanceIndex is out of range error [#8546](https://github.com/AnalyticalGraphicsInc/cesium/pull/8546)
+* Fixed a bug where rapidly updating a `PolylineCollection` could result in an instanceIndex is out of range error. [#8546](https://github.com/AnalyticalGraphicsInc/cesium/pull/8546)
+* Fixed a crash that could occur when an entity was deleted while the corresponding `Primitive` was being created asynchronously. [#8569](https://github.com/AnalyticalGraphicsInc/cesium/pull/8569)
 
 ### 1.65.0 - 2020-01-06
 
diff --git a/Source/DataSources/StaticGeometryColorBatch.js b/Source/DataSources/StaticGeometryColorBatch.js
index b8e3f8572411..c91067d16421 100644
--- a/Source/DataSources/StaticGeometryColorBatch.js
+++ b/Source/DataSources/StaticGeometryColorBatch.js
@@ -131,7 +131,7 @@ import Property from './Property.js';
                 primitive = new Primitive({
                     show : false,
                     asynchronous : true,
-                    geometryInstances : geometries,
+                    geometryInstances : geometries.slice(),
                     appearance : new this.appearanceType({
                         translucent : this.translucent,
                         closed : this.closed
diff --git a/Source/DataSources/StaticGeometryPerMaterialBatch.js b/Source/DataSources/StaticGeometryPerMaterialBatch.js
index 850209590347..59bd5ffb57ac 100644
--- a/Source/DataSources/StaticGeometryPerMaterialBatch.js
+++ b/Source/DataSources/StaticGeometryPerMaterialBatch.js
@@ -127,7 +127,7 @@ import Property from './Property.js';
                 primitive = new Primitive({
                     show : false,
                     asynchronous : true,
-                    geometryInstances : geometries,
+                    geometryInstances : geometries.slice(),
                     appearance : new this.appearanceType({
                         material : this.material,
                         translucent : this.material.isTranslucent(),
diff --git a/Source/DataSources/StaticGroundGeometryColorBatch.js b/Source/DataSources/StaticGroundGeometryColorBatch.js
index c565a3a092fc..79859d83b861 100644
--- a/Source/DataSources/StaticGroundGeometryColorBatch.js
+++ b/Source/DataSources/StaticGroundGeometryColorBatch.js
@@ -89,7 +89,7 @@ import Property from './Property.js';
                 primitive = new GroundPrimitive({
                     show : false,
                     asynchronous : true,
-                    geometryInstances : geometries,
+                    geometryInstances : geometries.slice(),
                     classificationType : this.classificationType
                 });
                 primitives.add(primitive, this.zIndex);
diff --git a/Source/DataSources/StaticGroundGeometryPerMaterialBatch.js b/Source/DataSources/StaticGroundGeometryPerMaterialBatch.js
index 7ddb610f66a7..e34e513f636f 100644
--- a/Source/DataSources/StaticGroundGeometryPerMaterialBatch.js
+++ b/Source/DataSources/StaticGroundGeometryPerMaterialBatch.js
@@ -119,7 +119,7 @@ import Property from './Property.js';
                 primitive = new GroundPrimitive({
                     show : false,
                     asynchronous : true,
-                    geometryInstances : geometries,
+                    geometryInstances : geometries.slice(),
                     appearance : new this.appearanceType({
                         material : this.material
                         // translucent and closed properties overridden
diff --git a/Source/DataSources/StaticGroundPolylinePerMaterialBatch.js b/Source/DataSources/StaticGroundPolylinePerMaterialBatch.js
index 4794d6702715..317cc0c1732b 100644
--- a/Source/DataSources/StaticGroundPolylinePerMaterialBatch.js
+++ b/Source/DataSources/StaticGroundPolylinePerMaterialBatch.js
@@ -121,7 +121,7 @@ import Property from './Property.js';
                 primitive = new GroundPolylinePrimitive({
                     show : false,
                     asynchronous : this._asynchronous,
-                    geometryInstances : geometries,
+                    geometryInstances : geometries.slice(),
                     appearance : new this.appearanceType(),
                     classificationType : this.classificationType
                 });
diff --git a/Source/DataSources/StaticOutlineGeometryBatch.js b/Source/DataSources/StaticOutlineGeometryBatch.js
index f37ed8bee20a..03feea0bcd5f 100644
--- a/Source/DataSources/StaticOutlineGeometryBatch.js
+++ b/Source/DataSources/StaticOutlineGeometryBatch.js
@@ -90,7 +90,7 @@ import Property from './Property.js';
                 primitive = new Primitive({
                     show : false,
                     asynchronous : true,
-                    geometryInstances : geometries,
+                    geometryInstances : geometries.slice(),
                     appearance : new PerInstanceColorAppearance({
                         flat : true,
                         translucent : this.translucent,