I think that this can sometimes happen if you have a custom/ user-defined function, or have copied the formulae in from another worksheet.
I don't know what causes it, and it's never happened to me, but I understand that you can try the following two things to overcome it: 1.
We’d like to give it custom formatting, so it looks more like a time from a stopwatch.
We want to give it the format: [h]:mm:ss To do this, start by selecting the column. Choose Custom and type in the format you want to use for the numbers. Notice nothing has changed, even though it shows “Custom” in the Number Format drop-down.
The defined named can help you increase your work pace.
However, the reference range in the name will not update automatically.
And the experienced experts will give you the right suggestion.
However, data recovery is not as easy as you may think.
But here you can also use the OFFSET function for the name. Except for the above methods, here you can also use the table for the source range.
Thus, whenever you add new items in the range, this defined name will also update automatically. When you meet with Excel corruption, you will certainly need to fix it as soon as possible.
Use Ctrl-Alt-F9 (instead of the normal F9) to force calculations across the worksheet. Find and replace = with = (equal sign with equal sign) - apparently this can solve the problem.
There’s a quirk with Microsoft Excel 2010 (and possibly other versions) where custom number formats don’t get applied to existing data.