diff --git a/MatterControlLib/PartPreviewWindow/MainViewWidget.cs b/MatterControlLib/PartPreviewWindow/MainViewWidget.cs
index a52b71642..1f6c094b3 100644
--- a/MatterControlLib/PartPreviewWindow/MainViewWidget.cs
+++ b/MatterControlLib/PartPreviewWindow/MainViewWidget.cs
@@ -545,15 +545,23 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 					MinimumSize = new Vector2(120, theme.TabButtonHeight)
 				};
 
-				printerTab.CloseClicked += (s, e) =>
+				void Tab_CloseClicked(object sender, EventArgs args)
 				{
 					ApplicationController.Instance.ClosePrinter(printer);
-				};
+				}
 
+				void Widget_Closed(object sender, EventArgs args)
+				{
+					// Unregister listeners
+					printerTab.CloseClicked -= Tab_CloseClicked;
+					printerTab.Closed -= Widget_Closed;
+					printer.Settings.SettingChanged -= Printer_SettingChanged;
+				}
+
+				// Register listeners
 				printer.Settings.SettingChanged += Printer_SettingChanged;
-
-				// Unregister listener on Tab close
-				printerTab.Closed += (s, e) => printer.Settings.SettingChanged -= Printer_SettingChanged;
+				printerTab.CloseClicked += Tab_CloseClicked;
+				printerTab.Closed += Widget_Closed;
 
 				// Add printer tab
 				tabControl.AddTab(printerTab);
@@ -609,10 +617,19 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 
 			tabControl.AddTab(partTab);
 
-			partTab.CloseClicked += (s, e) =>
+			void Tab_CloseClicked(object sender, EventArgs args)
 			{
 				ApplicationController.Instance.Workspaces.Remove(workspace);
-			};
+			}
+
+			void Widget_Closed(object sender, EventArgs args)
+			{
+				partTab.CloseClicked -= Tab_CloseClicked;
+				partTab.Closed -= Widget_Closed;
+			}
+
+			partTab.CloseClicked += Tab_CloseClicked;
+			partTab.Closed += Widget_Closed;
 
 			return partTab;
 		}
diff --git a/MatterControlLib/PartPreviewWindow/RunningTasksWidget.cs b/MatterControlLib/PartPreviewWindow/RunningTasksWidget.cs
index 8fc92bdf9..7e9aeb066 100644
--- a/MatterControlLib/PartPreviewWindow/RunningTasksWidget.cs
+++ b/MatterControlLib/PartPreviewWindow/RunningTasksWidget.cs
@@ -27,6 +27,7 @@ of the authors and should not be interpreted as representing official policies,
 either expressed or implied, of the FreeBSD Project.
 */
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using MatterHackers.Agg;
@@ -67,14 +68,23 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 			};
 			this.AddChild(pendingTasksList);
 
-			var tasks = ApplicationController.Instance.Tasks;
+			// Register listeners
+			ApplicationController.Instance.Tasks.TasksChanged += this.Tasks_TasksChanged;
 
-			tasks.TasksChanged += (s, e) =>
-			{
-				RenderRunningTasks(theme, tasks);
-			};
+			this.RenderRunningTasks(theme, ApplicationController.Instance.Tasks);
+		}
 
-			RenderRunningTasks(theme, tasks);
+		private void Tasks_TasksChanged(object sender, EventArgs e)
+		{
+			this.RenderRunningTasks(theme, ApplicationController.Instance.Tasks);
+		}
+
+		public override void OnClosed(EventArgs e)
+		{
+			// Unregister listeners
+			ApplicationController.Instance.Tasks.TasksChanged -= this.Tasks_TasksChanged;
+
+			base.OnClosed(e);
 		}
 
 		private void RenderRunningTasks(ThemeConfig theme, RunningTasksConfig tasks)
diff --git a/MatterControlLib/PartPreviewWindow/View3D/MeshViewerWidget.cs b/MatterControlLib/PartPreviewWindow/View3D/MeshViewerWidget.cs
index 76830781f..f2d081378 100644
--- a/MatterControlLib/PartPreviewWindow/View3D/MeshViewerWidget.cs
+++ b/MatterControlLib/PartPreviewWindow/View3D/MeshViewerWidget.cs
@@ -66,6 +66,7 @@ namespace MatterHackers.MatterControl.PartPreviewWindow
 
 		private readonly List<IDrawable> drawables = new List<IDrawable>();
 		private readonly List<IDrawableItem> itemDrawables = new List<IDrawableItem>();
+
 		private bool emulatorHooked;
 		private long lastEmulatorDrawMs;
 		private readonly Mesh emulatorNozzleMesh = PlatonicSolids.CreateCube(1, 1, 10);