I have simple Form Application, this app contain separated socket Task. This Task handles send(string) procedure for sending message to Server. Server sends back message to client, Task receives Message and raise Event, that invoke last onReceived(){ Console.WriteLine(“{0}”, e.Message)}. This all works very well.

My question is: Why this process not works, when is in onReceived event procedure added code of richEditBox?.

onReceived with Console.Writeline(“Message”); works.

onReceived with any of RichEditBox object not works.

Example, that not works:

communicator.onReceived(object sender, ExtraEventArgs e){ richTextBox.AppendText(“Message”); }