Working with a list, but I keep getting errors when updating

eladhtn From the looks of it you are trying to set-up a data validation list. That can be done by entering the options in the List box separated by commas or by referencing a range in the worksheet that is either on a single row or column.

From your screenshot I conclude that you referenced a range of merged cells that spans 2 columns. That simply not allowed. Unmerge these cells and then re-sleect the list of options. I guess that this will change the reference to R1C3:R10C3. If you really want to keep the merged cells, manually override the reference that Excel created to span only column 3, rows 1 to 10.