I have a dashboard chart widget whose source data is a report on a sheet. There are times when the report accurately returns no data from the sheet that meets the reporting filter criteria. In that case, the dashboard chart widget displays an 'Unable to display chart' error (screenshot below).
This error message is inaccurate and leads the users to believe there is a configuration error or something broken in the chart or the underlying report. This effect is worsened during troubleshooting when attempting to edit the widget, and seeing the prompt to 'Add Data'.
The chart widget and the report are correctly configured, it's just that the report has returned no data. Based on the report configuration, 'no data' is an occasional accurate and intended output. With that output, the chart widget should display something more informative and accurate, like the same chart that was there before, just with '0' displayed for each measured parameter.
Does anyone have a solution for this? I had temporary success with a 'Summarize' configuration on the report, but that was apparently only due to ghost data coming through from the source sheet. Once I cleaned up the ghost data, the 'Summarize' configuration failed to resolve the issue again.