Linked file error

I have a spreadsheet which was used last year and I copied it then renemed the copy.
(Old was named Accounts - 2019-2020; New is renamed Accounts - 2020-2021)
Everytime I open the renamed (new) file I get an error that says it can't find a linked file.
I am CERTAIN that the unfound file is not required.
I tried to breal the link but it refuses to break it.
I ran a third party link finder and it says that the file is linked but not any formulas or functions.
How do I get rid of the link and this error?

There are other places to look for links.
Charts/Graphs may have ranges linked to other files. Named ranges could be referencing other files. Conditional Formatting even may be the issue.
Impossible to say where your links are without seeing the file.

BSB