Non-existent link

My workbook contains a link to a source it cannot find.

I cannot find any reference to this source in my workbook.

I added a new blank worksheet
Deleted every other sheet
Deleted every module
Deleted every line of code

what remains is a workbook with 1 blank worksheet and a Link it cannot find the sourse file and I cannot delete this link.

How can I eliminate this non-existent link?