I have a file that when it opens I get the warning saying cannot update
links. When I open the Edit Links dialog the problem file is listed as
Source Not Found.

However, there are no links to this file in my spreadsheet. I have used Edit
Find with the filename and also Edit Find to check every single link. It is
not there.

Change Source does not work, nothing happens. Break Link doesn't work
(although I want other links to remain!).

I reinstated the problem file and then tried using Edit Links to change the
source etc. but still no luck.

I need to be able to distribute this file to others without the message
appearing, yet I need some users to be able to choose whether to update links
or not when they open it.

Please help.