Microsoft Office 2000 Binder

After opening Office Binder or creating new Office Binder, the error message "document type is not compatible with Office Binders". I am trying to drag Word 2000 files to the left side of Binder as explained in the Office Binder Section. I've tried Section and Add From File; same error. The first time I opened or created Office Binder after recent install, the drag and drop worked great with no errors. Are there different procedures for dragging Word documents vs Excel documents?