Scott, the call frmServer.smi_OnAfterMessageReceived fails with an InvalidOperationException: "Cross-thread operation not valid: Control 'txtRequest' accessed from a thread other than the thread it was created on.". Here's a lazy man's workaround for this: void smi_OnAfterReceiveRequest(object source, MessageInspectorArgs args) { try { txtRequest.Text = args.RequestEnvelope; } catch (InvalidOperationException ex) { this.Invoke(new Server.ServerMessageInspector.MessageInspectorEventHandler(smi_OnAfterReceiveRequest), source, args); } } Likewise for frmServer.smi_OnBeforeRequestReceived.

That's the problem with the UI thread.do the following: 1. Add this in the class SynchronizationContext _uiSyncContext; 2.Then write the following two methods. public void Showdata(string t) { SendOrPostCallback callback = delegate(object state) { this.LoadData(state.ToString()); }; _uiSyncContext.Post(callback, t); } public void LoadData(string msg) { txtRequest.Text = msg; } 2. Add the following : void smi_OnAfterReceiveRequest(object source, MessageInspectorArgs args) { Showdata(args.RequestEnvelope.ToString()); } Cheers! rajuChandra