diff --git a/SafeExamBrowser.I18n.Contracts/TextKey.cs b/SafeExamBrowser.I18n.Contracts/TextKey.cs
index 85393ab7..caa74a9f 100644
--- a/SafeExamBrowser.I18n.Contracts/TextKey.cs
+++ b/SafeExamBrowser.I18n.Contracts/TextKey.cs
@@ -119,6 +119,8 @@ namespace SafeExamBrowser.I18n.Contracts
 		MessageBox_ReloadConfirmationTitle,
 		MessageBox_RemoteSessionNotAllowed,
 		MessageBox_RemoteSessionNotAllowedTitle,
+		MessageBox_ServerReconfigurationWarning,
+		MessageBox_ServerReconfigurationWarningTitle,
 		MessageBox_ServiceUnavailableError,
 		MessageBox_ServiceUnavailableErrorTitle,
 		MessageBox_ServiceUnavailableWarning,
diff --git a/SafeExamBrowser.I18n/Data/de.xml b/SafeExamBrowser.I18n/Data/de.xml
index 7057dfaa..e2dcd89d 100644
--- a/SafeExamBrowser.I18n/Data/de.xml
+++ b/SafeExamBrowser.I18n/Data/de.xml
@@ -315,6 +315,12 @@
     <Entry key="MessageBox_RemoteSessionNotAllowedTitle">
         Remote-Sitzung erkannt
     </Entry>
+    <Entry key="MessageBox_ServerReconfigurationWarning">
+        Es besteht bereits eine SEB Server Verbindung. Es kann keine andere SEB Server Verbindung aufgebaut werden.
+    </Entry>
+    <Entry key="MessageBox_ServerReconfigurationWarningTitle">
+        Rekonfiguration Nicht Erlaubt
+    </Entry>
     <Entry key="MessageBox_ServiceUnavailableError">
         Fehler beim Initialisieren des SEB-Service! SEB wird sich nun beenden da der Service als obligatorisch konfiguriert ist.
     </Entry>
diff --git a/SafeExamBrowser.I18n/Data/en.xml b/SafeExamBrowser.I18n/Data/en.xml
index 1df9527a..55bc1311 100644
--- a/SafeExamBrowser.I18n/Data/en.xml
+++ b/SafeExamBrowser.I18n/Data/en.xml
@@ -315,6 +315,12 @@
     <Entry key="MessageBox_RemoteSessionNotAllowedTitle">
         Remote Session Detected
     </Entry>
+    <Entry key="MessageBox_ServerReconfigurationWarning">
+        There is already a SEB Server session running. It is not allowed to reconfigure for another SEB Server session.
+    </Entry>
+    <Entry key="MessageBox_ServerReconfigurationWarningTitle">
+        Reconfiguration Not Allowed
+    </Entry>
     <Entry key="MessageBox_ServiceUnavailableError">
         Failed to initialize the SEB service! SEB will now terminate since the service is configured to be mandatory.
     </Entry>
diff --git a/SafeExamBrowser.Runtime/Operations/ServerOperation.cs b/SafeExamBrowser.Runtime/Operations/ServerOperation.cs
index b69dad6b..078f2c46 100644
--- a/SafeExamBrowser.Runtime/Operations/ServerOperation.cs
+++ b/SafeExamBrowser.Runtime/Operations/ServerOperation.cs
@@ -19,6 +19,7 @@ using SafeExamBrowser.Server.Contracts;
 using SafeExamBrowser.Server.Contracts.Data;
 using SafeExamBrowser.Settings;
 using SafeExamBrowser.SystemComponents.Contracts;
+using SafeExamBrowser.UserInterface.Contracts.MessageBox;
 
 namespace SafeExamBrowser.Runtime.Operations
 {
@@ -98,7 +99,15 @@ namespace SafeExamBrowser.Runtime.Operations
 		{
 			if (Context.Current.Settings.SessionMode == SessionMode.Server)
 			{
-				InitializeNextSession();
+				if (Context.Next.Settings.SessionMode == SessionMode.Server)
+				{
+					ShowReconfigurationError();
+					return OperationResult.Aborted;
+				}
+				else 
+				{
+					return Revert();
+				}
 			}
 			else if (Context.Next.Settings.SessionMode == SessionMode.Server)
 			{
@@ -107,7 +116,6 @@ namespace SafeExamBrowser.Runtime.Operations
 
 			return OperationResult.Success;
 		}
-
 		public override OperationResult Revert()
 		{
 			var result = OperationResult.Success;
@@ -256,5 +264,19 @@ namespace SafeExamBrowser.Runtime.Operations
 
 			return success;
 		}
+
+		private void ShowReconfigurationError()
+		{
+			var args = new MessageEventArgs 
+			{ 
+				Action = MessageBoxAction.Ok,
+				Icon = MessageBoxIcon.Warning,
+				Message = TextKey.MessageBox_ServerReconfigurationWarning,
+				Title = TextKey.MessageBox_ServerReconfigurationWarningTitle
+			};
+			logger.Warn("Server reconfiguration requested but is not allowed.");
+
+			ActionRequired?.Invoke(args);
+		}
 	}
 }