Object variable or With block variable not set

[mobidv]

Hi,

I seem to be getting the above error every now and again. It happens maybe 5 times out of 6.

This is the code that it's getting stuck on (the third line):

    Dim rng As Range
    Set rng = Nothing
    Set rng = ActiveWorkbook.Sheets("Data").Range("CA1:CF9").SpecialCells(xlCellTypeVisible)

Any help would be appreciated.