diff --git a/CSharp/Engines/WindowsForms/Libraries/UniversalEditor.UserInterface.WindowsForms/Editor.cs b/CSharp/Engines/WindowsForms/Libraries/UniversalEditor.UserInterface.WindowsForms/Editor.cs
index aec37327..961f2a91 100644
--- a/CSharp/Engines/WindowsForms/Libraries/UniversalEditor.UserInterface.WindowsForms/Editor.cs
+++ b/CSharp/Engines/WindowsForms/Libraries/UniversalEditor.UserInterface.WindowsForms/Editor.cs
@@ -165,7 +165,10 @@ namespace UniversalEditor.UserInterface.WindowsForms
 			// FIXME: refactor this into a single XML configuration file loader at the beginning of engine launch
 			if (System.IO.Directory.Exists(configurationPath))
 			{
-				string[] fileNames = System.IO.Directory.GetFiles(configurationPath, System.Configuration.ConfigurationManager.AppSettings["UniversalEditor.Configuration.ConfigurationFileNameFilter"]);
+				string configurationFileNameFilter = System.Configuration.ConfigurationManager.AppSettings["UniversalEditor.Configuration.ConfigurationFileNameFilter"];
+				if (configurationFileNameFilter == null) configurationFileNameFilter = "*.uexml";
+
+				string[] fileNames = System.IO.Directory.GetFiles(configurationPath, configurationFileNameFilter);
 				XMLPropertyListDataFormat xmpl = new XMLPropertyListDataFormat();
 				
 				foreach (string fileName in fileNames)
diff --git a/CSharp/Libraries/UniversalEditor.Essential/Common/Reflection.cs b/CSharp/Libraries/UniversalEditor.Essential/Common/Reflection.cs
index 5753f5b3..9d967559 100644
--- a/CSharp/Libraries/UniversalEditor.Essential/Common/Reflection.cs
+++ b/CSharp/Libraries/UniversalEditor.Essential/Common/Reflection.cs
@@ -199,8 +199,11 @@ namespace UniversalEditor.Common
 
 			foreach (string path in paths)
 			{
+				string configurationFileNameFilter = System.Configuration.ConfigurationManager.AppSettings["UniversalEditor.Configuration.ConfigurationFileNameFilter"];
+				if (configurationFileNameFilter == null) configurationFileNameFilter = "*.uexml";
+
 				string[] XMLFileNames = null;
-				XMLFileNames = System.IO.Directory.GetFiles(path, System.Configuration.ConfigurationManager.AppSettings["UniversalEditor.Configuration.ConfigurationFileNameFilter"], System.IO.SearchOption.AllDirectories);
+				XMLFileNames = System.IO.Directory.GetFiles(path, configurationFileNameFilter, System.IO.SearchOption.AllDirectories);
 				foreach (string fileName in XMLFileNames)
 				{
 #if !DEBUG
diff --git a/CSharp/Libraries/UniversalEditor.UserInterface/Engine.cs b/CSharp/Libraries/UniversalEditor.UserInterface/Engine.cs
index 560179c5..576070d1 100644
--- a/CSharp/Libraries/UniversalEditor.UserInterface/Engine.cs
+++ b/CSharp/Libraries/UniversalEditor.UserInterface/Engine.cs
@@ -525,7 +525,10 @@ namespace UniversalEditor.UserInterface
 		protected virtual void InitializeXMLConfiguration()
 		{
 			#region Load the XML files
-			string[] xmlfiles = System.IO.Directory.GetFiles(mvarBasePath, System.Configuration.ConfigurationManager.AppSettings["UniversalEditor.Configuration.ConfigurationFileNameFilter"], System.IO.SearchOption.AllDirectories);
+			string configurationFileNameFilter = System.Configuration.ConfigurationManager.AppSettings["UniversalEditor.Configuration.ConfigurationFileNameFilter"];
+			if (configurationFileNameFilter == null) configurationFileNameFilter = "*.uexml";
+
+			string[] xmlfiles = System.IO.Directory.GetFiles(mvarBasePath, configurationFileNameFilter, System.IO.SearchOption.AllDirectories);
 
 			UpdateSplashScreenStatus("Loading XML configuration files", 0, 0, xmlfiles.Length);