Index: Application/Application.Ringtoets/App.xaml.cs
===================================================================
diff -u -rcd5c998302b1ee9c6d3b1455faa36236cb2da613 -r78a113ae4b3a1cd879ff171bed5e5562bf13a62e
--- Application/Application.Ringtoets/App.xaml.cs	(.../App.xaml.cs)	(revision cd5c998302b1ee9c6d3b1455faa36236cb2da613)
+++ Application/Application.Ringtoets/App.xaml.cs	(.../App.xaml.cs)	(revision 78a113ae4b3a1cd879ff171bed5e5562bf13a62e)
@@ -2,13 +2,15 @@
 using System.Collections.Generic;
 using System.Configuration;
 using System.Diagnostics;
+using System.Globalization;
 using System.IO;
 using System.Linq;
 using System.Reflection;
 using System.Threading;
 using System.Windows;
 using System.Windows.Controls.Primitives;
 using System.Windows.Forms;
+using System.Windows.Markup;
 using Core.Common.Base;
 using Core.Common.Base.Workflow;
 using Core.Common.Controls.Swf;
@@ -59,6 +61,11 @@
         {
             RingtoetsApplication.SetLanguageAndRegionalSettions(Settings.Default);
 
+            FrameworkElement.LanguageProperty.OverrideMetadata(
+                typeof(FrameworkElement),
+                new FrameworkPropertyMetadata(
+                    XmlLanguage.GetLanguage(CultureInfo.CurrentCulture.IetfLanguageTag)));
+
             log.Info(Core.Common.Gui.Properties.Resources.App_App_Starting_Ringtoets____);
         }
 
Index: Application/Application.Ringtoets/app.config
===================================================================
diff -u -rec61b187052d8d8ae6cddd3fc1d0546608d9b0c2 -r78a113ae4b3a1cd879ff171bed5e5562bf13a62e
--- Application/Application.Ringtoets/app.config	(.../app.config)	(revision ec61b187052d8d8ae6cddd3fc1d0546608d9b0c2)
+++ Application/Application.Ringtoets/app.config	(.../app.config)	(revision 78a113ae4b3a1cd879ff171bed5e5562bf13a62e)
@@ -29,7 +29,7 @@
     <!--    <add key="licenseFilePath" value="license.lic" /> -->
     <!-- outputlog4net's debug information to the Visual Studio output debug window -->
     <!-- <add key="log4net.Internal.Debug" value="true" /> -->
-    <add key="language" value="en-US" />
+    <add key="language" value="nl" />
     <!--<add key="language" value="nl-NL" />-->
     <!-- check http://msdn.microsoft.com/en-us/goglobal/bb896001.aspx for a list of possible values -->
     <add key="ClientSettingsProvider.ServiceUri" value="" />