When copying complex objects to the clipboard, then switching to the Finder and selecting Show Clipboard, you may see the message "Unable to Display the Clipboard. "
The Finder displays this message because it doesn't have enough memory to display the contents of the clipboard when it contains complex objects. These complex objects include large smoothed polygons, freehands, bezigons, EPSF objects or large color bitmaps. The objects are, in fact, in the clipboard and will paste into a document in another application.
To view the contents of these objects in the Finder, you can allocate it more memory, just as you can allocate more memory to MacDraw Pro. For more information, see the section on Memory in the MacDraw Pro Troubleshooting Guide.