I have one workbook which all of a sudden started showing numbers displayed as 254-789 rather than 254,789. My default language is English and my regional setting is English (United States). When I try to format the cell it treats it as if it is some kind of negative number.
I've attached a workbook which is the result of copying some of the data from the problem workbook.
Does anyone have any suggestions to fix it? Recreating the workbook would be very difficult.