I have a named dynamic range with the source
=OFFSET(Data!$J$2,0,0,COUNTA(Data!$J:$J),1)
Thia is set up as the data validation list in a cell with a drop down
list It is set so that once the drop down is activated there is the
option of selecting a blank from the bottom of the list so that if you
activate the cell in error you don't have to delete any entry you are
forced to make, you can select the blank and leave the cell blank. This
works fine until the list gets quite long at which time there is no
option of a blank.I don't know the number in the list where this starts
but certainly a list over 100 has this problem. On shorter lists the
blank is selectable. The selection is correct as when you check the
named list it shows the correct range. I would welcome any views on
solving this if it can be resolved.

Kind regards
Graham Haughs
Turriff
Scotland