diff --git a/src/Views/TextDiffView.axaml.cs b/src/Views/TextDiffView.axaml.cs
index b74347ce..99f91618 100644
--- a/src/Views/TextDiffView.axaml.cs
+++ b/src/Views/TextDiffView.axaml.cs
@@ -1145,6 +1145,8 @@ namespace SourceGit.Views
 
         public void ForceSyncScrollOffset()
         {
+            if (_scrollViewer == null)
+                return;
             if (DataContext is ViewModels.TwoSideTextDiff diff)
                 diff.SyncScrollOffset = _scrollViewer.Offset;
         }
@@ -1584,7 +1586,7 @@ namespace SourceGit.Views
 
             CurrentChangeBlockIdxProperty.Changed.AddClassHandler<TextDiffView>((v, e) =>
             {
-                if (v.Editor.Presenter != null)
+                if ((int)e.NewValue >= 0 && v.Editor.Presenter != null)
                 {
                     foreach (var p in v.Editor.Presenter.GetVisualDescendants().OfType<ThemedTextDiffPresenter>())
                     {