Linking to other workbooks is a very common task in Excel, but sometimes you might find yourself with a workbook that has links you can’t find even though Excel tells you they exist.
There is no automatic way to find all external references that are used in a workbook, however, there are several manual methods you can use to find them. You need to look in

a) formulas,
b) defined names,
c) objects (like text boxes or shapes),
d) chart titles, and chart data series.
e) conditional formats
f) data validations

It is always not easy to find such links. In a financial model these links can threaten model integrity usually causing non-responsiveness to input changes in the output.

Using the add-in is easy and it allows you to find the exact cells with addresses, named ranges, chart objects, etc. The add-in reports all such instances in a tabular format in a separate sheet.

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Installation instructions:
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- 1) Open Excel and Go to File->Excel Options->Add-ins.
- 2) In Manage drop-down select Excel Add-ins and press Go.
[Excel shortcut Alt, T, I]
- 3) Now go to Browse and navigate to the Add-in file. Press Open and then Ok.

This should bring up the FL Add-in Tab in the Ribbon.