diff --git a/MatterControlLib/ApplicationView/Config/ThumbnailsConfig.cs b/MatterControlLib/ApplicationView/Config/ThumbnailsConfig.cs
index 4369ad0ec..b5b8cd855 100644
--- a/MatterControlLib/ApplicationView/Config/ThumbnailsConfig.cs
+++ b/MatterControlLib/ApplicationView/Config/ThumbnailsConfig.cs
@@ -178,7 +178,7 @@ namespace MatterHackers.MatterControl
 				CacheFilename(libraryItem, width, height));
 		}
 
-		internal void QueueForGeneration(Func<Task> func)
+		public void QueueForGeneration(Func<Task> func)
 		{
 			lock (ThumbsLock)
 			{
diff --git a/MatterControlLib/Library/Providers/FileSystem/SceneReplacementFileItem.cs b/MatterControlLib/Library/Providers/FileSystem/SceneReplacementFileItem.cs
deleted file mode 100644
index 946c529f6..000000000
--- a/MatterControlLib/Library/Providers/FileSystem/SceneReplacementFileItem.cs
+++ /dev/null
@@ -1,40 +0,0 @@
-/*
-Copyright (c) 2017, John Lewin
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are met:
-
-1. Redistributions of source code must retain the above copyright notice, this
-   list of conditions and the following disclaimer.
-2. Redistributions in binary form must reproduce the above copyright notice,
-   this list of conditions and the following disclaimer in the documentation
-   and/or other materials provided with the distribution.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-The views and conclusions contained in the software and documentation are those
-of the authors and should not be interpreted as representing official policies,
-either expressed or implied, of the FreeBSD Project.
-*/
-
-
-namespace MatterHackers.MatterControl.Library
-{
-	public class SceneReplacementFileItem : FileSystemFileItem
-	{
-		public SceneReplacementFileItem(string filePath)
-			: base(filePath)
-		{
-		}
-	}
-}
diff --git a/MatterControlLib/Library/Providers/LibraryConfig.cs b/MatterControlLib/Library/Providers/LibraryConfig.cs
index 2605a0a3c..673c0e678 100644
--- a/MatterControlLib/Library/Providers/LibraryConfig.cs
+++ b/MatterControlLib/Library/Providers/LibraryConfig.cs
@@ -207,11 +207,13 @@ namespace MatterHackers.MatterControl.Library
 				&& ApplicationSettings.ValidFileExtensions.Contains(fileExtensionLower);
 		}
 
-		public async Task LoadItemThumbnail(Action<ImageBuffer> thumbnailListener, Action<MeshContentProvider> buildThumbnail, ILibraryItem libraryItem, ILibraryContainer libraryContainer, int thumbWidth, int thumbHeight, ThemeConfig theme)
+		public async Task LoadItemThumbnail(Action<ImageBuffer> thumbnailListenerIn, Action<MeshContentProvider> buildThumbnail, ILibraryItem libraryItem, ILibraryContainer libraryContainer, int thumbWidth, int thumbHeight, ThemeConfig theme)
 		{
 			async void setItemThumbnail(ImageBuffer icon)
 			{
-				if (icon != null)
+				var thumbnailListener = thumbnailListenerIn;
+
+                if (icon != null)
 				{
 					if (icon.Width == 0)
 					{
diff --git a/MatterControlLib/PartPreviewWindow/View3D/View3DWidget.cs b/MatterControlLib/PartPreviewWindow/View3D/View3DWidget.cs
index 7afbc88b0..196409821 100644
--- a/MatterControlLib/PartPreviewWindow/View3D/View3DWidget.cs
+++ b/MatterControlLib/PartPreviewWindow/View3D/View3DWidget.cs
@@ -1233,7 +1233,7 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 
 			if ((firstItem is ILibraryAssetStream contentStream
 				&& contentStream.ContentType == "gcode")
-				|| firstItem is SceneReplacementFileItem)
+				|| firstItem is FileSystemFileItem)
 			{
 				DragDropObject = null;
 				this.SceneReplacement = firstItem as ILibraryAssetStream;
diff --git a/MatterControlLib/PartPreviewWindow/ViewToolBarControls.cs b/MatterControlLib/PartPreviewWindow/ViewToolBarControls.cs
index 5d4923d25..51a99b5a8 100644
--- a/MatterControlLib/PartPreviewWindow/ViewToolBarControls.cs
+++ b/MatterControlLib/PartPreviewWindow/ViewToolBarControls.cs
@@ -610,7 +610,7 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 					int maxItemWidth = 0;
 
 					var recentFiles = new DirectoryInfo(ApplicationDataStorage.Instance.PlatingDirectory).GetFiles("*.mcx").OrderByDescending(f => f.LastWriteTime);
-					foreach (var item in recentFiles.Where(f => f.Length > 215).Select(f => new SceneReplacementFileItem(f.FullName)).Take(12))
+					foreach (var item in recentFiles.Where(f => f.Length > 215).Select(f => new FileSystemFileItem(f.FullName)).Take(12))
 					{
 						var imageBuffer = new ImageBuffer(thumbWidth, thumbWidth);