This is not always the case. Of course when there is a link that doesn't
work I would expect to receive the error message. However, I have also
clicked on "Edit Links" for some files and found that the window reports that
all links are "Ok."

"Spiky" wrote:

The problem is probably that your workbooks have been moved, renamed,
or deleted. Or worksheets in those workbooks. Or, you have a cell or
two that have typos.

You can try updating links to the proper workbooks, or finding typos.

Or, muddan suggested turning off the warning. But that won't help if
you actually have links that aren't working and you need them to work.