diff --git a/src/BreCalClient/EditShipcallControl.xaml b/src/BreCalClient/EditShipcallControl.xaml
index 8f20e1b..ae2df90 100644
--- a/src/BreCalClient/EditShipcallControl.xaml
+++ b/src/BreCalClient/EditShipcallControl.xaml
@@ -65,24 +65,15 @@
                 <ColumnDefinition Width=".5*" />
                 <ColumnDefinition Width=".5*" />
             </Grid.ColumnDefinitions>
-            <ComboBox Name="comboBoxArrivalBerth" Grid.Column="0" Margin="2" DisplayMemberPath="Name"  SelectedValuePath="Id">
-                <ComboBox.ContextMenu>
-                    <ContextMenu>
-                        <MenuItem Header="{x:Static p:Resources.textClearValue}" Name="contextMenuItemDepartureBerth" Click="contextMenuItemDepartureBerth_Click" />
-                    </ContextMenu>
-                </ComboBox.ContextMenu>
-            </ComboBox>
-            <ComboBox Name="comboBoxDepartureBerth" Grid.Column="1" Margin="2" DisplayMemberPath="Name" SelectedValuePath="Id">
-                <ComboBox.ContextMenu>
-                    <ContextMenu>
-                        <MenuItem Header="{x:Static p:Resources.textClearValue}" Name="contextMenuItemArrivalBerth" Click="contextMenuItemArrivalBerth_Click" />
-                    </ContextMenu>
-                </ComboBox.ContextMenu>
-            </ComboBox>
+            <ComboBox Name="comboBoxArrivalBerth" Grid.Column="0" Margin="2" DisplayMemberPath="Name"  SelectedValuePath="Id" SelectionChanged="comboBoxArrivalBerth_SelectionChanged"/>
+
+            <ComboBox Name="comboBoxDepartureBerth" Grid.Column="1" Margin="2" DisplayMemberPath="Name" SelectedValuePath="Id" SelectionChanged="comboBoxDepartureBerth_SelectionChanged"/>
+
+
         </Grid>
         
-        <xctk:DateTimePicker x:Name="datePickerETA" Grid.Column="3" Grid.Row="2" Margin="2" Format="Custom" FormatString="dd.MM. yyyy  HH:mm" IsEnabled="False"/>
-        <xctk:DateTimePicker x:Name="datePickerETD" Grid.Column="3" Grid.Row="3" Margin="2" Format="Custom" FormatString="dd.MM. yyyy  HH:mm" IsEnabled="False"/>
+        <xctk:DateTimePicker x:Name="datePickerETA" Grid.Column="3" Grid.Row="2" Margin="2" Format="Custom" FormatString="dd.MM. yyyy  HH:mm" IsEnabled="False" ValueChanged="datePickerETA_ValueChanged"/>
+        <xctk:DateTimePicker x:Name="datePickerETD" Grid.Column="3" Grid.Row="3" Margin="2" Format="Custom" FormatString="dd.MM. yyyy  HH:mm" IsEnabled="False" ValueChanged="datePickerETD_ValueChanged"/>
 
         <Label Content="{x:Static p:Resources.textAgency}" Grid.Column="2" Grid.Row="4"  HorizontalContentAlignment="Right"/>
         <ComboBox Name="comboBoxAgency" Grid.Column="3" Grid.Row="4" Margin="2" DisplayMemberPath="Name" SelectedValuePath="Id" SelectionChanged="comboBoxAgency_SelectionChanged">
diff --git a/src/BreCalClient/EditShipcallControl.xaml.cs b/src/BreCalClient/EditShipcallControl.xaml.cs
index 9c157e7..2456bd9 100644
--- a/src/BreCalClient/EditShipcallControl.xaml.cs
+++ b/src/BreCalClient/EditShipcallControl.xaml.cs
@@ -66,8 +66,7 @@ namespace BreCalClient
         }
 
         private void comboBoxShip_SelectionChanged(object sender, SelectionChangedEventArgs e)
-        {
-            this.buttonOK.IsEnabled = this.comboBoxShip.SelectedItem != null;
+        {            
             if (this.comboBoxShip.SelectedItem != null)
             {
                 Ship? ship = this.comboBoxShip.SelectedItem as Ship;
@@ -83,11 +82,13 @@ namespace BreCalClient
                 this.doubleUpDownLength.Value = null;
                 this.doubleUpDownWidth.Value = null;
             }
+            this.CheckForCompletion();
         }
 
         private void comboBoxAgency_SelectionChanged(object sender, SelectionChangedEventArgs e)
         {
             this.EnableControls();
+            this.CheckForCompletion();
         }
 
         private void comboBoxCategories_SelectionChanged(object? sender, SelectionChangedEventArgs? e)
@@ -121,6 +122,7 @@ namespace BreCalClient
                         break;
                 }
             }
+            this.CheckForCompletion();
         }
 
         #endregion
@@ -132,22 +134,24 @@ namespace BreCalClient
             this.comboBoxAgency.SelectedIndex = -1;
             this.ShipcallModel.AssignedParticipants.Remove(Extensions.ParticipantType.AGENCY);
         }
-
-        private void contextMenuItemArrivalBerth_Click(object sender, RoutedEventArgs e)
-        {
-            this.comboBoxArrivalBerth.SelectedIndex = -1;
-            this.ShipcallModel.Berth = "";
-        }
-
-        private void contextMenuItemDepartureBerth_Click(object sender, RoutedEventArgs e)
-        {
-            this.comboBoxDepartureBerth.SelectedIndex -= 1;
-        }        
-
+        
         #endregion
 
         #region private methods
 
+        void CheckForCompletion()
+        {
+            bool isEnabled = true;
+
+            isEnabled &= this.comboBoxShip.SelectedItem != null;
+            isEnabled &= this.comboBoxCategories.SelectedItem != null;
+            isEnabled &= ((this.comboBoxArrivalBerth.SelectedItem != null) || (this.comboBoxDepartureBerth.SelectedItem != null));
+            isEnabled &= (this.datePickerETA.Value.HasValue || this.datePickerETD.Value.HasValue);
+            isEnabled &= this.comboBoxAgency.SelectedItem != null;
+
+            this.buttonOK.IsEnabled = isEnabled;
+        }
+
         private void CopyToModel()
         {
             if (this.ShipcallModel.Shipcall != null)
@@ -292,5 +296,24 @@ namespace BreCalClient
 
         #endregion
 
+        private void datePickerETA_ValueChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
+        {
+            this.CheckForCompletion();
+        }
+
+        private void datePickerETD_ValueChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
+        {
+            this.CheckForCompletion();
+        }
+
+        private void comboBoxArrivalBerth_SelectionChanged(object sender, SelectionChangedEventArgs e)
+        {
+            this.CheckForCompletion();
+        }
+
+        private void comboBoxDepartureBerth_SelectionChanged(object sender, SelectionChangedEventArgs e)
+        {
+            this.CheckForCompletion();
+        }
     }
 }
diff --git a/src/BreCalClient/MainWindow.xaml b/src/BreCalClient/MainWindow.xaml
index 39ba515..3d89272 100644
--- a/src/BreCalClient/MainWindow.xaml
+++ b/src/BreCalClient/MainWindow.xaml
@@ -36,7 +36,7 @@
                 <Label Content="{x:Static p:Resources.textPassword}" Grid.Row="2" VerticalContentAlignment="Center" />
                 <TextBox Name="textUsername" Grid.Row="1" Grid.Column="1" Margin="2" VerticalContentAlignment="Center" />
                 <PasswordBox Name="textPassword" Grid.Row="2" Grid.Column="1" Margin="2" VerticalContentAlignment="Center"  PasswordChar="*"/>
-                <Label Name="labelLoginResult" Grid.Row="3" Grid.ColumnSpan="2" HorizontalContentAlignment="Center" VerticalContentAlignment="Center" />
+                <Label Name="labelLoginResult" Grid.Row="3" Grid.ColumnSpan="2" HorizontalContentAlignment="Center" VerticalContentAlignment="Center" FontWeight="Bold" />
                 <Button Name="buttonLogin" Content="{x:Static p:Resources.textLogin}" Grid.Row="4" Grid.Column="0" Margin="2" Click="buttonLogin_Click" IsDefault="True" />
                 <Button Name="buttonExit" Content="{x:Static p:Resources.textExit}" Grid.Row="4" Grid.Column="1" Margin="2" Click="buttonExit_Click" />
             </Grid>
diff --git a/src/BreCalClient/MainWindow.xaml.cs b/src/BreCalClient/MainWindow.xaml.cs
index f9e31c6..3402794 100644
--- a/src/BreCalClient/MainWindow.xaml.cs
+++ b/src/BreCalClient/MainWindow.xaml.cs
@@ -17,6 +17,8 @@ using BreCalClient.misc.Model;
 
 using static BreCalClient.Extensions;
 using System.Collections.Concurrent;
+using Newtonsoft.Json;
+using System.Security.Principal;
 
 namespace BreCalClient
 {
@@ -129,7 +131,13 @@ namespace BreCalClient
             }
             catch (ApiException ex)
             {
-                this.labelLoginResult.Content = ex.Message;
+                if ((ex.ErrorContent != null && ((string)ex.ErrorContent).StartsWith("{"))) {
+                    Error? anError = JsonConvert.DeserializeObject<Error>((string)ex.ErrorContent);
+                    this.labelLoginResult.Content = anError?.Message ?? ex.Message;
+                }
+                else {
+                    this.labelLoginResult.Content = ex.Message;
+                }
                 labelGeneralStatus.Text = $"Connection {ConnectionStatus.FAILED}";
             }
             catch (Exception ex)