Using Date() works in Access 2007, but not with Access 2007 Runtime. Gives #Name?

I have an unbound text box on a report using:

=Format(Date(),"Medium Date") or =Format(Date(),"dd/mm/yyyy")

 as the control source.

This works fine in a Win 7 PC having Access 2007, but when these reports are created on a certain Win 10 PC using Access 2007 Runtime, it displays #Name?.
Another Win 10 PC using Access 2007 runtime displays the correct date format.

There are no table fields in the record source named Date. The Region settings in all PCs are identical.

Any advice greatly appreciated.