Getting update pop up but have no external links

[Shodi]

Hi everyone. I have a work book with 23 sheets with basic IF, SEARCH, ISNUMBER, SUM, AVERAGE and IFERROR formulae and data validation, all in the same workbook.
I have not linked any cell or formula to a external source.
But every time I open the workbook I get a pop up "This workbook contains links to one or more external sources that could be unsafe" and then gives the option for "Update", "Don't Update" and "Cancel".
Like I mentioned there is no link to an external source that I have inserted.
How do I find the source/cause of this popup?
I am afraid that the data I have in the 23 sheets may be corrupted or altered in some way if this persists.
Please help.

 

[RoryA]

Have you tried using Bill Manville's FindLink add-in to see if it can locate the source of the link?

 

[Shodi]

Thanks Rory. I downloaded Bill Manville's FindLink add-in it did the job.
However I am curious to know. The external reference that my workbook was popping up was due to a sheet named Hong Kong. All the links that referred to this sheet was replaced by Findlink.
The other sheets are named with single names like Bahrain, Malaysia, UAE etc.
Did the external reference happen because the sheet name was two words. If so is there a way around this??

 

[RoryA]

No, that would not cause an external link. You'd only get that if the link was to a sheet by that name in another workbook.