There is a large amount if information on the Clipboard
When closing a 
workbook object with the .close method, Excel might display a message that says There is a large amount of information on the clipboard. Do you want to be able to paste this information into another program later?:
Unfortunately, this message cannot be turned of by simply setting
application.displayAlerts to false. Microsoft recommends to prevent this message with one of the execute one of the following three statements before closing the workbook: -
activeSheet.range("a1").copy -
application.cutCopyMode = false -
wb.save