Richard's computer recently updated Windows 10 and now his Excel charts that have trendlines all have a little message in the top-left corner stating "trendline error." Richard doesn't know if this is related to the Windows update or not, but he needs to understand why the message appeared and how to remove it.
The appearance of this message wasn't caused by an update in Windows, but by an update in the Office 365 version of Excel. The first reports about this message were near the end of July, so it is a relatively recent issue. You can see it discussed in this Microsoft forum:
https://techcommunity.microsoft.com/t5/excel/chart-displaying-quot-trendline-error-quot/m-p/1538964
The participants indicated that the error occurs when the X values (those indicated along the horizontal axis) are either 0 or very close in value to each other. This results in a calculated "infinite slope" that cannot provide any meaningful trend that can be displayed.
It seems, though, that the message may also appear in places it shouldn't. For instance, take a look at this discussion on a different Microsoft forum:
https://answers.microsoft.com/en-us/msoffice/forum/all/pivot-chart-trending-error/e1471b3e-ad2c-4776-837a-c42fa6410f9b
In this case, the message was appearing on PivotCharts, even when the chart did not contain a trendline. In this instance, the appearance of the message is definitely an error, and was reported to Microsoft. This means that it should be corrected—at least for charts that contain no trendlines—in a future release of the program.
It remains to be seen whether the fix, when it comes, will affect those charts where the X values are close to the same. It is also unclear whether Microsoft will make it a configuration option to display or not display this message. In the meantime, the only solution would be to try removing the trendlines for those charts where a trendline makes little sense.
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2021-04-28 15:55:25
Pat
Frustratingly enough I am experiencing this same error and have yet to find a way to troubleshoot. Thank you for posting the forum links, hopefully I'll turn up something.
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