Can't Unlink Old Macro Workbook

One of the departments in my company has a series of workbooks they use that were linked to some macro workbooks a very long time ago. The links are all broken, but I can't figure out how to remove the links.

There's no VBA in the workbooks, so it's not a WorkbookOpen event. And when I open the linked macro workbooks, there isn't any VBA in there either.

There's a popup that says "Cannot find BudgetMacroWkbk.xls!AddMENUMenu, which has been assigned to run each time Example File.xlsm is opened. Continuing could cause errors. Cancel opening Example File.xlsm?"

I'm at a loss. Any ideas?

I've attached a copy of the workbook. Password to open is "Prod18" which is another issue where I can't figure out how to eliminate the password.

Thanks for your quick response, Marvin. It didn't work though.

The password delete should be
File - Save As - Tools (at the bottom left beside the "save" button) - General Options - delete the passwords in the little windows, OK , Save
Can't find anything that works yet for breaking the links.