Details.
One thing in general, if SAS shows an error the best way to ask questions about the error is to copy the code that generates the error and the error plus any notes or messages from the log. Copy and then paste into a code box opened on the forum with the </> icon. The code box is important as the message windows will reformat text and can removed/distort some of the diagnostic information that the log often contains.
If the error doesn't allow you to get to the log then take a screen shot of what you are getting and share that plus the code running when the error occurred.
Common issues around DDE include timing, any of attempting to do multiple things to a single file faster than the DDE can process, instructions incompatible with specific file formats (and EVERY office release change the file format as far as DDE is concerned), spelling such as incorrectly referencing at sheet name (spaces may be hard to count) and other applications using the DDE connection "address".
