New feature as of August 2019.
This is additional content for the book, “Data Analysis with Microsoft Power BI.” It fits after page 208.
Conditional Formatting Warnings
If an error is detected within the conditional formatting definition of a field, a warning indicator is displayed.
The Conditional Format Warning Indicator
The warning indicator will appear in the Format tab of the Visualization pane when the visualization containing that item is selected. The warning indicator appears as a yellow triangle containing an exclamation point. Hovering the mouse pointer over this warning indicator will display a popup message similar to:
If modern visual headers are enabled for the report, the warning will appear similar to:
The Detailed Error Message
Clicking the warning indicator will display a detailed error message similar to the following:
The detailed error message may indicate the problem is in the Values area of the Format tab (pane). This is incorrect. If there is a conditional formatting error, it must be corrected in the “Conditional formatting” area of the Format tab.
Fixing a Conditional Formatting Error
To fix the indicated problem, go to the Format tab of the Visualization pane and expand the “Conditional formatting” area. The warning indicator may appear on the Values area of the Format tab. However, that is not the area to look in to remedy a conditional formatting error.
In the dropdown list at the top of the “Conditional formatting” area, select the field indicated by the detailed error message. Click the “Advanced controls” link for the property with the conditional formatting error as specified by the popup message or the detailed error message. In the example above, the error was found in the conditional formatting of the background color of a field called “% of Reduction Goal.” Modify the conditional formatting definition to alleviate the issue.