Find Method error: -Object variable with block set variable not set

Hi all again
I have a code exported from other wb which worked normally.
When it was imported into new wb Find method gives an error RunTime 91 Object variable with block set variable not set

     Dim i As Long, TDateCNum As Long
     TDateCNum = Cells.Find(What:=MyDate, LookIn:=xlValues).Column

I just want to find column number of today's date and us it in Cells()
I was able to do it on old wb but not here

Thanks in advance...