Hyperlinks won't work when file is viewed in email

[Guest]

I have a hyperlink to another file in an Excel workbook, which works fine
when opened from within Excel. However, if I send the email as an attachment
and a user opens and views (doesn't save) the email, the hyperlinks won't
work. Any idea why? Thanks.

 

[Guest]

Excel may not have established a base reference yet.

 

[Guest]

What is a base reference and how can I fix this?

Excel may not have established a base reference yet.