Hi VeraSluijter,
Thank you for querying in this forum.
From your description, it seems that you are trying saving a Excel file with waterfall chart, however, there is an error message appeared when you re-opened the Excel file.
And same problem still persists when you copied the data into new file.
May I know if my understanding is right? If so, we have tested it on our side and we cannot reproduce the same situation as yours.
Given the situation you encountered, we’d suggest you create a new Excel file and create simple data instead of copying the data, then you can use waterfall chart to check if the same problem will occur. If the same problem still persists, this issue may be related to your Excel file. And we will give you some suggestions below and hope that will help you:
According to the version you provided, it seems that you are not using the latest version, we’d suggest you refer to this article: Update history for Microsoft 365 Apps to achieve the latest version of Office. Then you can update your Office to the latest version to check if the same problem will occur.
You can open your Excel in safe mode to check if the same problem will occur. It will help in identifying an add-in or extension that may be causing a problem on startup. As steps shown below: Right-click the Start button (lower-left corner) in Windows, and click Run.> In the Run box, type one of the command: excel /safe
You can use Online Repair to fix the Office application. Repair an Office application.
If the same problem still persists after trying the suggestions above, to better understand your situation, could you provide the information below?
Could you provide the Product Information and version of your Excel? You can go to Excel > File > Account and provide the screenshot of it.
May I know if you are using VBA code in this file? If so, we’d suggest you create a new Excel file and use new data without using VBA code to check if the same problem will occur. May I know if the other format of files have the same problem? For example, .xlsx.
Could you provide the screenshot of error message?
Best Regards,
Sukie