diff --git a/AsyncRAT-C#/AsyncRAT-Sharp/Forms/Form1.cs b/AsyncRAT-C#/AsyncRAT-Sharp/Forms/Form1.cs
index 4bfe1eb..9d29a07 100644
--- a/AsyncRAT-C#/AsyncRAT-Sharp/Forms/Form1.cs
+++ b/AsyncRAT-C#/AsyncRAT-Sharp/Forms/Form1.cs
@@ -414,7 +414,7 @@ namespace AsyncRAT_Sharp
                             Debug.WriteLine("task removed");
                             return;
                         }
-                        foreach (Clients client in Settings.Online)
+                        foreach (Clients client in Settings.Online.ToList())
                         {
                             if (!asyncTask.doneClient.Contains(client.ID))
                             {