diff --git a/PartPreviewWindow/View3D/View3DCreateSelecitonData.cs b/PartPreviewWindow/View3D/View3DCreateSelecitonData.cs
index 75a298629..fd73a8185 100644
--- a/PartPreviewWindow/View3D/View3DCreateSelecitonData.cs
+++ b/PartPreviewWindow/View3D/View3DCreateSelecitonData.cs
@@ -116,6 +116,7 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 				else if (pendingPartsToLoad.Count > 0)
 				{
 					LoadAndAddPartsToPlate(pendingPartsToLoad.ToArray());
+					pendingPartsToLoad.Clear();
 				}
 				else
 				{
diff --git a/PartPreviewWindow/View3D/View3DWidget.cs b/PartPreviewWindow/View3D/View3DWidget.cs
index 3db866ed7..c18a69753 100644
--- a/PartPreviewWindow/View3D/View3DWidget.cs
+++ b/PartPreviewWindow/View3D/View3DWidget.cs
@@ -601,6 +601,7 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 					else
 					{
 						LoadAndAddPartsToPlate(pendingPartsToLoad.ToArray());
+						pendingPartsToLoad.Clear();
 					}
 				}
 			}