Excel 2013 Chart label not displaying

Hi everyone,
I have a workbook, which I use for different departments that displays a number of different pie charts and I have found that a particular pie chart omits a specific label repeatedly. The pie chart displays the wedge within the chart itself, but does not display the label. At the moment I have data labels with percentages. All other labels display, of which there are 7. I found a solution that fixes the problem each time it arises and that is to select Chart Tools/Format/Series 1 data labels and then Format Selection. When I then select any data label, I click on "Clone Current Label" and the missing label appears with the correct percentage amount.
I was wondering if the problem is a common one, or if there is a more permanent solution.
I use the workbook for multiple uses and rather than have it present as a template (*.xltm), it is a macro-enabled spreadsheet (*.xlsm). Could this be related to the problem?
Many thanks in advance for your help.
Cheers,
Spero.

Hi,

Did you try deleting that particular pie chart and creating a new one? Sometimes it works.

Hi Chatrody,
Yes, I had tried that previously and it did work then, but now it has arisen again. Deleting and replacing takes a lot longer than the cloning process. Part of the problem is that the original file is distributed to a number of users who input their own data. My role is to keep it together while they build their own files. After a time, i think it starts generating this kind of error when more and more users copy their files from the original. I have various protections in place to stop anyone changing formulas, but I can't do the same for charts, as it prevents formatting as well. Frustrating.

I just wanted to say I also have this problem and your solution helped me. I was not able to get the number in the series for one set on the graph after updating the graph. I couldn't figure it out. This helped a bunch. Thanks!