DDE channel not fully closed; awaiting response from foreign application
Your Visual Basic application has terminated one DDE conversation with another application and has attempted to start a new conversation, but the other application has not finished handling the termination of the first conversation.
The other application is waiting for a response from the user. Switch to that application and take an action appropriate to the message it is displaying.
Your code is not yielding to allow other applications to handle events. Call the DoEvents function and try establishing the link again.