Thread: Shared Workbook caused Macro to stop working

Using Excel 2007.

I started getting the following message as soon as I shared our workbook.
Run-time error '1004':
Application-defined or object-defined error

The macro itself is very simple:

Sub HyperLink()
ActiveCell.Hyperlinks.Add ActiveCell, "http://(hidden)" & ActiveCell.Value
End Sub

Any way I can recode it to be compliant?