diff --git a/MatterControl.OpenGL/GCodeRenderer/GCodeVertexBuffer.cs b/MatterControl.OpenGL/GCodeRenderer/GCodeVertexBuffer.cs
index 35e6d62f3..8fd781279 100644
--- a/MatterControl.OpenGL/GCodeRenderer/GCodeVertexBuffer.cs
+++ b/MatterControl.OpenGL/GCodeRenderer/GCodeVertexBuffer.cs
@@ -200,8 +200,8 @@ namespace MatterHackers.GCodeVisualizer
 			{
 				UiThread.RunOnIdle(() =>
 				{
-					GL.DeleteBuffers(1, ref vertexID);
-					GL.DeleteBuffers(1, ref indexID);
+					GL.DeleteBuffer(vertexID);
+					GL.DeleteBuffer(indexID);
 				});
 
 				disposed = true;
diff --git a/MatterControlLib/PartPreviewWindow/PrinterTabPage.cs b/MatterControlLib/PartPreviewWindow/PrinterTabPage.cs
index d6d6b42d0..7aff1f8e8 100644
--- a/MatterControlLib/PartPreviewWindow/PrinterTabPage.cs
+++ b/MatterControlLib/PartPreviewWindow/PrinterTabPage.cs
@@ -818,7 +818,7 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 				// setup the message row
 				{
 					// when it is done queue it to the change to gcode stream
-					var switchMessage = "Switch to new G-Code?\n\nBefore you switch, check that your are seeing the changes you expect.".Localize();
+					var switchMessage = "Switch to new G-Code?\n\nBefore you switch, check that you are seeing the changes you expect.".Localize();
 					resliceMessageRow.AddChild(new WrappedTextWidget(switchMessage, theme.DefaultFontSize, textColor: theme.TextColor)
 					{
 						Margin = new BorderDouble(7, 3)
diff --git a/Submodules/agg-sharp b/Submodules/agg-sharp
index 3298dfc8d..234cca570 160000
--- a/Submodules/agg-sharp
+++ b/Submodules/agg-sharp
@@ -1 +1 @@
-Subproject commit 3298dfc8dda49d127473203f63144d900b5edd13
+Subproject commit 234cca570dfc282a9ed892efa5ac34c5739dd966