At this point, I can only open MyCostPro worksheet by starting Excel through Applications in Windows, then opening the version of MyCostPro stored on Onedrive. In otherwords, trying to open the worksheet from the Desktop icon gives me this error. I really can't have this happening, Scott can you help me out here? Thanks! I have rebuilt MOST of the file data, another hour it should be mostly there (lost 34 days worth of Inventory source/purchase dates, and I have 34 days worth of sold inventory still in my product master, and all Mileage and Expense records for the last 34 days are gone).