Should this type of formula be entered a special way

I am getting a REF# error on my sheets and I noticed when I copied from another sheet it did not copy the {}. When I enter this type of formula do I just press enter or does it need something else because when I hit enter all i see in the cell is the { but on the sheet I copied it from it does not have it .... it is clean


{= OFFSET($V$2:$V$501,MAX( ROW($W$2:$W$501))-ROW(), 0)}



Why on one sheet I get the Error but the other I do not? I know the rows are different but what am I missing, this is driving me crazy all afternoon

Thank you!