To see a list of all changes that have been made to a cell, right-click on the cell and select Show History: then select a period, or enter a Date range and click OK.
The History dialog displays the values held in the cell during the selected period, in the order they were entered, up to a maximum of 1,000 changes. You can find and manually re-enter the data value if needed.
For more on Show History, see View change history for cells in a module or a dashboard grid.