diff --git a/GUIs.Common/frmNotification_Startup.vb b/GUIs.Common/frmNotification_Startup.vb
index 21bae37c..fd7d00c2 100644
--- a/GUIs.Common/frmNotification_Startup.vb
+++ b/GUIs.Common/frmNotification_Startup.vb
@@ -178,7 +178,7 @@ Public Class frmNotification_Startup
     Private Function GetOperationMode() As OperationMode
         Dim oOperationMode As OperationMode
 
-        If Environment.Service.Client.IsOnline AndAlso Environment.Service.Address <> String.Empty Then
+        If Environment.Service.Client?.IsOnline AndAlso Environment.Service.Address <> String.Empty Then
             oOperationMode = OperationMode.WithAppServer
         Else
             oOperationMode = OperationMode.NoAppServer