Occasionally, when Embed loads the Mathcad interface OLE control for the first time, you’ll see a Server Busy message. Just click Retry several times. Once the control is fully loaded, you will not see this message for the rest of your session.
To increase the time to wait before producing the Server Busy message, you can change the time out by adding OLEtimeout=xxx to the Configuration file. The default timeout is 30 sec.