diff --git a/src/Forms/Main.cs b/src/Forms/Main.cs
index 778706d6f..15e45008f 100644
--- a/src/Forms/Main.cs
+++ b/src/Forms/Main.cs
@@ -8016,15 +8016,15 @@ namespace Nikse.SubtitleEdit.Forms
 
         private void UpdateOverlapErrors(TimeCode startTime)
         {
-            labelStartTimeWarning.Text = string.Empty;
-            labelDurationWarning.Text = string.Empty;
+            string startTimeWarning = string.Empty;
+            string durationWarning = string.Empty;
             if (_subtitle.Paragraphs.Count > 0 && SubtitleListview1.SelectedItems.Count > 0 && startTime != null)
             {
                 int firstSelectedIndex = SubtitleListview1.SelectedItems[0].Index;
 
                 var prevParagraph = _subtitle.GetParagraphOrDefault(firstSelectedIndex - 1);
                 if (prevParagraph != null && prevParagraph.EndTime.TotalMilliseconds > startTime.TotalMilliseconds && Configuration.Settings.Tools.ListViewSyntaxColorOverlap)
-                    labelStartTimeWarning.Text = string.Format(_languageGeneral.OverlapPreviousLineX, prevParagraph.EndTime.TotalSeconds - startTime.TotalSeconds);
+                    startTimeWarning = string.Format(_languageGeneral.OverlapPreviousLineX, prevParagraph.EndTime.TotalSeconds - startTime.TotalSeconds);
 
                 var nextParagraph = _subtitle.GetParagraphOrDefault(firstSelectedIndex + 1);
                 if (nextParagraph != null)
@@ -8032,21 +8032,23 @@ namespace Nikse.SubtitleEdit.Forms
                     double durationMilliSeconds = GetDurationInMilliseconds();
                     if (startTime.TotalMilliseconds + durationMilliSeconds > nextParagraph.StartTime.TotalMilliseconds && Configuration.Settings.Tools.ListViewSyntaxColorOverlap)
                     {
-                        labelDurationWarning.Text = string.Format(_languageGeneral.OverlapX, ((startTime.TotalMilliseconds + durationMilliSeconds) - nextParagraph.StartTime.TotalMilliseconds) / TimeCode.BaseUnit);
+                        durationWarning = string.Format(_languageGeneral.OverlapX, ((startTime.TotalMilliseconds + durationMilliSeconds) - nextParagraph.StartTime.TotalMilliseconds) / TimeCode.BaseUnit);
                     }
 
-                    if (labelStartTimeWarning.Text.Length == 0 &&
+                    if (startTimeWarning.Length == 0 &&
                         startTime.TotalMilliseconds > nextParagraph.StartTime.TotalMilliseconds && Configuration.Settings.Tools.ListViewSyntaxColorOverlap)
                     {
                         double di = (startTime.TotalMilliseconds - nextParagraph.StartTime.TotalMilliseconds) / TimeCode.BaseUnit;
-                        labelStartTimeWarning.Text = string.Format(_languageGeneral.OverlapNextX, di);
+                        startTimeWarning = string.Format(_languageGeneral.OverlapNextX, di);
                     }
                     else if (numericUpDownDuration.Value < 0)
                     {
-                        labelDurationWarning.Text = _languageGeneral.Negative;
+                        durationWarning = _languageGeneral.Negative;
                     }
                 }
             }
+            labelStartTimeWarning.Text = startTimeWarning;
+            labelDurationWarning.Text = durationWarning;
         }
 
         private double GetDurationInMilliseconds()
@@ -11064,7 +11066,6 @@ namespace Nikse.SubtitleEdit.Forms
                 }
 
                 checkBoxSyncListViewWithVideoWhilePlaying.Checked = oldSync;
-                numericUpDownDuration.ValueChanged += NumericUpDownDurationValueChanged;
 
                 if (goToNext)
                 {