Conflict resolution in shared workbook due to same cell accessed by 2 user.
Cause:
Two users are entering data in the same cell and the worksheet contains data in a row below the last row of data in a list. The worksheet contains additional data in rows below the list being edited. Excel will not add another row in this case to avoid pushing data off the last row of the spreadsheet.
Solution:
Make sure the worksheet containing the data list does not contain any additional data below the last row of the data list on which is being entered.