I have a spreadsheet that has several columns that use data validation to
restrict the data input. It was working until a few minutes ago. Now the
drop down arrows no longer appear. If I go to Data Validation the menu
appears and has the correct list and range. But the arrows still do not
appear.

I cleared the validation and reentered it and still no arrows.

Has anyone ever encounted this? If so, how did it fix it.