Fix Nullreference error on Opening window, adde SCADA validator

Step.Config/ServerConfigController.cs

@@ -19,6 +19,8 @@ namespace Step.Config
 {
     public static class ServerConfigController
     {
+        private static string actualFileName; 
+
         public static void ReadStartupConfig()
         {
             try
@@ -64,6 +66,8 @@ namespace Step.Config
                     readerSettings.Add(null, schemaReader);
                 }
             }
+            
+            actualFileName = configFilePath;
 
             // Open file reader
             XDocument xmlConfigFile = XDocument.Load(BASE_PATH + "\\" + configFilePath);
@@ -73,6 +77,30 @@ namespace Step.Config
             return xmlConfigFile;
         }
 
+
+        private static void validateScada(string configSchemaFilePath, string configFilePath)
+        {
+            // Create new instance
+            XmlSchemaSet readerSettings = new XmlSchemaSet();
+
+            // Add Schema from Assembly
+            Assembly myAssembly = Assembly.GetExecutingAssembly();
+            using (Stream schemaStream = myAssembly.GetManifestResourceStream(configSchemaFilePath))
+            {
+                using (XmlReader schemaReader = XmlReader.Create(schemaStream))
+                {
+                    readerSettings.Add(null, schemaReader);
+                }
+            }
+
+            actualFileName = Path.GetFileName(configFilePath);
+
+            // Open file reader
+            XDocument xmlConfigFile = XDocument.Load(configFilePath);
+            // Validate file
+            xmlConfigFile.Validate(readerSettings, ValidationHandler);
+        }
+
         private static void SetAreaValueByName(XElement element)
         {
             // Choose which area to be set
@@ -140,7 +168,7 @@ namespace Step.Config
             {                
                 ExceptionManager.Manage(ERROR_LEVEL.FATAL,
                     // "Error while reading file: " + e.Exception.SourceUri +
-                    "Error while reading configuration file: " + e.Message,
+                    "Error while reading XML file \"" + actualFileName + "\" \n\n" + e.Message,
                     true
                     );
             }
@@ -192,9 +220,13 @@ namespace Step.Config
             // Cycle inside xml files
             foreach (var file in files)
             {
+                validateScada(SCADA_PAGES_SCHEMA_PATH, SCADA_DIRECTORY + file.Name);
+
                 StreamReader sr = new StreamReader(SCADA_DIRECTORY + file.Name);
                 XmlSerializer xmlSerializer = new XmlSerializer(typeof(ScadaSchemaModel));
                 ScadaSchemaModel schema = xmlSerializer.Deserialize(sr) as ScadaSchemaModel; 
+
+
                 // Setup incremental ids
                 schema.Id = i++;