diff --git a/EmoTracker.Data/AutoTracking/LuaMemorySegment.cs b/EmoTracker.Data/AutoTracking/LuaMemorySegment.cs
index 0aa0254..28e77d0 100644
--- a/EmoTracker.Data/AutoTracking/LuaMemorySegment.cs
+++ b/EmoTracker.Data/AutoTracking/LuaMemorySegment.cs
@@ -58,8 +58,6 @@ public LuaMemorySegment() : base()
 
         protected override void OnSegmentDataUpdated()
         {
-            base.OnSegmentDataUpdated();
-
             var state = this.OwnerState as Sessions.TrackerState;
             if (state == null) return;
             var scripts = state.Scripts;
@@ -76,10 +74,15 @@ protected override void OnSegmentDataUpdated()
             {
                 try
                 {
+                    object[] result;
                     using (new LocationDatabase.SuspendRefreshScope(state.Locations))
                     {
-                        scripts.SafeCall(callback, this);
+                        result = scripts.SafeCall(callback, this);
                     }
+                    bool succeeded = result != null && result.Length > 0
+                        && result[0] != null && !(result[0] is bool b && !b);
+                    if (succeeded)
+                        Dirty = false;
                 }
                 catch (Exception ex)
                 {
diff --git a/EmoTracker.Data/AutoTracking/MemorySegment.cs b/EmoTracker.Data/AutoTracking/MemorySegment.cs
index b1a7b0c..5ac3bf7 100644
--- a/EmoTracker.Data/AutoTracking/MemorySegment.cs
+++ b/EmoTracker.Data/AutoTracking/MemorySegment.cs
@@ -33,7 +33,7 @@ namespace EmoTracker.Data.AutoTracking
     /// data (override <see cref="OnSegmentDataUpdated"/>).
     /// </para>
     /// </summary>
-    public class MemorySegment : ModelTypeBase, IMemorySegment, IUpdateWithConnector, IDisposable
+    public abstract class MemorySegment : ModelTypeBase, IMemorySegment, IUpdateWithConnector, IDisposable
     {
         #region -- Global Event Hooks --
 
@@ -339,9 +339,7 @@ public MemoryUpdateResult UpdateWithConnector(IAutoTrackingProvider provider, Pa
         /// overrides to dispatch onto the UI thread and SafeCall the
         /// pack-supplied LuaFunction callback.
         /// </summary>
-        protected virtual void OnSegmentDataUpdated()
-        {
-        }
+        protected abstract void OnSegmentDataUpdated();
 
         public override void Dispose()
         {
diff --git a/EmoTracker.Data/Debugging/LuaDebuggee.cs b/EmoTracker.Data/Debugging/LuaDebuggee.cs
index db2eb6b..5557e53 100644
--- a/EmoTracker.Data/Debugging/LuaDebuggee.cs
+++ b/EmoTracker.Data/Debugging/LuaDebuggee.cs
@@ -667,6 +667,8 @@ void ServeRequest(DebugRequest req)
 
         internal void EnterExceptionPause(string errMessage, string traceback)
         {
+            if (!(LuaDebugServer.Instance?.HasActiveSession ?? false)) return;
+
             // Always log so we can confirm the upcall actually
             // reached us — the Lua-side handler's pcall around the
             // upcall would otherwise silently swallow any throw.