Either the field you're using is a hyperlink that points to your workbook, with no mergefields, or you've screwed up the implementation. You might also want to check out the '
Mailmerge Hyperlink ‘Click Here’ Insertion' topic in the '
Mailmerge Tips and Tricks' Sticky thread at the top of this forum:
https://www.msofficeforums.com/mail-merge/21803-mailmerge-tips-tricks.html