diff --git a/MatterControlLib/ApplicationView/AppContext.cs b/MatterControlLib/ApplicationView/AppContext.cs
index 77659d3f8..94d6d677c 100644
--- a/MatterControlLib/ApplicationView/AppContext.cs
+++ b/MatterControlLib/ApplicationView/AppContext.cs
@@ -180,7 +180,12 @@ namespace MatterHackers.MatterControl
 
 			markdownWidegt.Markdown = toolTipText;
 			markdownWidegt.Width = 350;
-			var maxLineWidth = markdownWidegt.Descendants<ParagraphX>().Max(i => i.MaxLineWidth);
+			var maxLineWidth = 0.0;
+			if (markdownWidegt.Descendants<ParagraphX>().Any())
+			{
+				maxLineWidth = markdownWidegt.Descendants<ParagraphX>().Max(i => i.MaxLineWidth);
+			}
+
 			markdownWidegt.Width = maxLineWidth + 15;
 
 			return markdownWidegt;
diff --git a/MatterControlLib/PartPreviewWindow/MainViewWidget.cs b/MatterControlLib/PartPreviewWindow/MainViewWidget.cs
index b30bf7b17..f6ade4fdc 100644
--- a/MatterControlLib/PartPreviewWindow/MainViewWidget.cs
+++ b/MatterControlLib/PartPreviewWindow/MainViewWidget.cs
@@ -821,7 +821,6 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 
 			var textWidget = partTab.Descendants<TextWidget>().First();
 			var tabPill = partTab.Descendants<SimpleTab.TabPill>().First();
-			partTab.ToolTipText = textWidget.Text;
 			tabPill.HAnchor = HAnchor.Stretch;
 			var closeBox = partTab.Descendants<ImageWidget>().FirstOrDefault();
 			if (closeBox != null)
@@ -852,7 +851,20 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 				}
 
 				partTab.MaximumSize = new Vector2(width, partTab.MaximumSize.Y);
-				partTab.Width = partTab.Width - 1;
+				partTab.Width -= 1;
+
+				// wait for this size change to take effect and update the tool tip
+				partTab.BoundsChanged += (s, e) =>
+				{
+					if (partTab.Width < partTab.MaximumSize.X)
+					{
+						partTab.ToolTipText = textWidget.Text;
+					}
+					else
+					{
+						partTab.ToolTipText = "";
+					}
+				};
 			}
 
 			partTab.HAnchor = HAnchor.Stretch;
diff --git a/MatterControlLib/PartPreviewWindow/Tabs.cs b/MatterControlLib/PartPreviewWindow/Tabs.cs
index d6a93f44c..7d02091db 100644
--- a/MatterControlLib/PartPreviewWindow/Tabs.cs
+++ b/MatterControlLib/PartPreviewWindow/Tabs.cs
@@ -525,6 +525,7 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 	public class ToolTab : SimpleTab
 	{
 		public Color InactiveTabColor { get; set; }
+
 		public Color ActiveTabColor { get; set; }
 
 		public override Color BorderColor
diff --git a/Submodules/agg-sharp b/Submodules/agg-sharp
index eae4b60fa..3623ff408 160000
--- a/Submodules/agg-sharp
+++ b/Submodules/agg-sharp
@@ -1 +1 @@
-Subproject commit eae4b60fa1bb1f507010102cd540e30c69b0f24d
+Subproject commit 3623ff4084d7c3b09e7b5bd0e5f0b2c5c7e408d9