Hi Paul ... I cannot say how appreciative I am of the effort you have put in to try to solve this mystery. The mystery continues as the results remain consistent.

Pictures are worth many words, so I hope they are helpful.

First ... the contents of vs_vh.range("B4"). There are no hidden spaces or characters according to the len formula applied to B4 in cel C4 (28 char)


Here is an image of the Datasource file through the eyes of Windows Explorer. The preview pane shows the worksheet 'CORE" for which the mailmerge refers.


As we go through the code, we get these messages ...
Confirmation of the mail merge document:



Confirmation of the data source and sql ...



Then, we get the weird 'select source' with workbook reference to 'Data1.xls"



With 'DATA1.xls' as seen in Windows Explorer... (which I manually or intentionally put there ... excel or word must have created it at some point in the SQL line. As you can see ... the worksheet name is crazy and there is no data)



And within minutes ...