diff --git a/csharp/App/SaliMax/src/Program.cs b/csharp/App/SaliMax/src/Program.cs
index 8a857c7db..fd63b0882 100644
--- a/csharp/App/SaliMax/src/Program.cs
+++ b/csharp/App/SaliMax/src/Program.cs
@@ -170,6 +170,16 @@ internal static class Program
             Watchdog.NotifyAlive();
 
             var record = ReadStatus();
+
+            // If control Special Error return true, we must stop the system.(break;)
+            var specialErrorOccured = record.ControlSpecialError();
+            
+            if (specialErrorOccured.Item1)
+            {
+                //stop the system
+                //return
+                specialErrorOccured.Item2.WriteLine();
+            }
             
             record.ControlConstants();
             record.ControlSystemState();
@@ -202,6 +212,36 @@ internal static class Program
         // ReSharper disable once FunctionNeverReturns
     }
 
+    private static (Boolean, String) ControlSpecialError (this StatusRecord r) // to find a better name
+    {
+        //     Those errors must not occurs. Stop the system in case this is happen.
+        var isSpecialErrorOccured = false;
+        var errorMessage = "No Error";
+        
+        //     1. relay0 is open and K2 Close. 
+        if (r.Relays is { K2ConnectIslandBusToGridBus: false, K2IslandBusIsConnectedToGridBus: true } )
+        {
+            isSpecialErrorOccured = true;
+            errorMessage = " Contradiction: R0 is opening the K2 but the K2 is still close ";
+        }
+        
+        //     2. If K1 is open, K2 must be open . 
+        if (r.Relays is { K1GridBusIsConnectedToGrid: false, K2IslandBusIsConnectedToGridBus: true } )
+        {
+            isSpecialErrorOccured = true;
+            errorMessage = " Contradiction: K1 is open but the K2 is still close ";
+        }
+        
+        //     3.  If FI error is occured, K2 must be open. 
+        if (r.Relays is { FiError: true, K2IslandBusIsConnectedToGridBus: true } )
+        {
+            isSpecialErrorOccured = true;
+            errorMessage = " Contradiction: Fi error occured but the K2 is still close ";
+        }
+        
+        
+        return (isSpecialErrorOccured, errorMessage);
+    }
 
     private static void ControlConstants(this StatusRecord r)
     {
@@ -228,7 +268,7 @@ internal static class Program
         dcDevices.ForEach(d => d.Control.VoltageLimits.MaxBatteryVoltage             = configFile.MaxChargeBatteryVoltage);
         dcDevices.ForEach(d => d.Control.VoltageLimits.MinBatteryVoltage             = configFile.MinDischargeBatteryVoltage);
         dcDevices.ForEach(d => d.Control.ControlMode                                 = DcControlMode.VoltageDroop);
-        
+
         r.DcDc.ResetAlarms();
         r.AcDc.ResetAlarms();
     }