diff --git a/MatterControlLib/PartPreviewWindow/View3D/TrackballTumbleWidgetExtended.cs b/MatterControlLib/PartPreviewWindow/View3D/TrackballTumbleWidgetExtended.cs
index 939ea36de..0168eef66 100644
--- a/MatterControlLib/PartPreviewWindow/View3D/TrackballTumbleWidgetExtended.cs
+++ b/MatterControlLib/PartPreviewWindow/View3D/TrackballTumbleWidgetExtended.cs
@@ -349,14 +349,20 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 				ZeroVelocity();
 			}
 
-			var rayAtPosition = world.GetRayForLocalBounds(position);
-			var hitAtPosition = hitPlane.GetClosestIntersection(rayAtPosition);
+			if (hitPlane != null)
+			{
+				var rayAtPosition = world.GetRayForLocalBounds(position);
+				var hitAtPosition = hitPlane.GetClosestIntersection(rayAtPosition);
 
-			var offset = hitAtPosition.HitPosition - mouseDownWorldPosition;
-			bedCenter += offset;
-			world.Translate(offset);
+				if (hitAtPosition != null)
+				{
+					var offset = hitAtPosition.HitPosition - mouseDownWorldPosition;
+					bedCenter += offset;
+					world.Translate(offset);
 
-			Invalidate();
+					Invalidate();
+				}
+			}
 		}
 
 		public void ZeroVelocity()
diff --git a/Submodules/MatterSlice b/Submodules/MatterSlice
index 16e9e5a2b..a2bfc7651 160000
--- a/Submodules/MatterSlice
+++ b/Submodules/MatterSlice
@@ -1 +1 @@
-Subproject commit 16e9e5a2b5ff60df9c39d084e7820f346ac48111
+Subproject commit a2bfc7651149af674638c5925789a72acf557e23
diff --git a/Submodules/agg-sharp b/Submodules/agg-sharp
index ef102435a..d7dec9cc6 160000
--- a/Submodules/agg-sharp
+++ b/Submodules/agg-sharp
@@ -1 +1 @@
-Subproject commit ef102435a4a6250caf7599fb6a889089b46a19b7
+Subproject commit d7dec9cc62b55e5dd55655fa0456caba9f845252