diff --git a/BeWo/View/Detail/Report/AbwesenheitsView.xaml b/BeWo/View/Detail/Report/AbwesenheitsView.xaml
index ae06d3bbb..12b1fd4f5 100644
--- a/BeWo/View/Detail/Report/AbwesenheitsView.xaml
+++ b/BeWo/View/Detail/Report/AbwesenheitsView.xaml
@@ -144,7 +144,7 @@
         <DataTemplate x:Key="AppointmentTooltipContentTemplate" />
 
     </localView:BeWoView.Resources>
-    <Grid>
+    <Grid x:Name="_RootGrid">
         <GroupBox Header="Abwesenheiten" Style="{StaticResource ObjectEditGroupBox}">
             <Grid>
                 <Grid.ColumnDefinitions>
diff --git a/BeWo/View/Detail/Report/AbwesenheitsView.xaml.cs b/BeWo/View/Detail/Report/AbwesenheitsView.xaml.cs
index dd88ae6e3..a7ac71d0b 100644
--- a/BeWo/View/Detail/Report/AbwesenheitsView.xaml.cs
+++ b/BeWo/View/Detail/Report/AbwesenheitsView.xaml.cs
@@ -13,6 +13,8 @@ using DevExpress.XtraScheduler;
 using System;
 using System.Collections.Generic;
 using System.Linq;
+// Claude - Task für async/await-Unterstützung (Hintergrundladen)
+using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Forms;
@@ -77,18 +79,37 @@ namespace BeWo.View.Detail.Report
 
         public List<CompactTeamDC> SelectedTeams => FilterTeams.SelectedItems.Cast<CompactTeamDC>().ToList();
         
-        private void Button_Click(object sender, RoutedEventArgs e)
+        // Claude - Servicaufrufe laufen asynchron im Hintergrund; WaitLayer2 zeigt Ladeindikator;
+        //        - Hauptfenster wird während des Ladens komplett deaktiviert (keine Interaktion möglich)
+        private async void Button_Click(object sender, RoutedEventArgs e)
         {
             UpdateFilter();
-            
+
             SelectedMonth = _MonthPicker.SelectedMonth;
             SelectedYear = (int)_YearPicker.SelectedItem;
 
-            UrlaubsplanerRootObj = ServiceFacade.DoEmployeeServiceSync(s => s.BuildUrlaubsplanerRootObject(_SelectedFilter));
+            var waitLayer = new WaitLayer2();
+            _RootGrid.Children.Add(waitLayer);
+            BeWoApp.CurrentBeWo.MainWindow.IsEnabled = false;
 
-            UpdateScheduler(false);
-            ColorizeFeiertage();
-            ApplyFeiertagCellStyle();
+            try
+            {
+                var filter = _SelectedFilter;
+                UrlaubsplanerRootObj = await Task.Run(() =>
+                    ServiceFacade.DoEmployeeServiceSync(s => s.BuildUrlaubsplanerRootObject(filter)));
+
+                var absenceOverview = await Task.Run(() =>
+                    ServiceFacade.DoEmployeeServiceSync(x => x.GetAbsenceOverview(filter)));
+
+                UpdateScheduler(false, absenceOverview);
+                ColorizeFeiertage();
+                ApplyFeiertagCellStyle();
+            }
+            finally
+            {
+                _RootGrid.Children.Remove(waitLayer);
+                BeWoApp.CurrentBeWo.MainWindow.IsEnabled = true;
+            }
         }
 
         private void ColorizeFeiertage()
@@ -254,10 +275,14 @@ namespace BeWo.View.Detail.Report
             
         }
 
-        public void UpdateScheduler(bool neuLaden)
+        // Claude - optionaler Parameter absenceOverview: vorgeladene Daten aus Button_Click werden übergeben, um doppelten Serviceaufruf zu vermeiden
+        public void UpdateScheduler(bool neuLaden, List<EmployeeDC> absenceOverview = null)
         {
             var absenceReasons = _AbsenceReasonDCs;
-            var absenceOverview = ServiceFacade.DoEmployeeServiceSync(x => x.GetAbsenceOverview(_SelectedFilter));
+
+            if (absenceOverview == null)
+                absenceOverview = ServiceFacade.DoEmployeeServiceSync(x => x.GetAbsenceOverview(_SelectedFilter));
+
             _ListOfEmployee = absenceOverview;
             var start = new DateTime(_SelectedFilter.Year, _SelectedFilter.Month, 1);