Link to Excel Sheet no longer updates

[Isit Ears]

Hi

I have an access database with a link to an Excel File (all data is stored
and updated in the excel file). When I used to open up Access it would warn
me that "Unsafe safe expressions are not blocked, Do you want to block unsafe
expressions?" - And I accidently clicked Yes - and now the linked data will
never update.

How can I reverse this

Thanks