Prohibit a cell from being marked as complete


Hi everyone,

Does anyone know how you can keep someone from completing a line item? I have a sheet where I ask for a resolution to an issue and some users are marking the item as complete without providing the details of the resolution. I would like to block them from the cell until data is entered into the resolution cell. Does this make sense.

I have attached a photo of the portion of the sheet that is in question.

Thanks in advance!