sql_er this may explain your problem
When you save a workbook, Microsoft Office Excel stores only the part of each worksheet that contains data or formatting. Empty cells may contain formatting that causes the last cell in a row or column to fall outside of the range of cells that contains data. This causes the file size of the workbook to be larger than necessary and may result in more printed pages when you print the worksheet or workbook.
To avoid these issues, you can locate the last cell that contains data or formatting on a worksheet, and then reset that last cell by clearing all of the formatting that may be applied in empty rows or columns between the data and the last cell.
Let's say you enter any text or number in cell A10 and then enter a valid date in cell A20 of a new Worksheet. Now delete the date in cell A20 and save. This is because entering a date in A20 has caused Excel to automatically format the cell from "General" to a Date format.
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