Your layer is based on a feature class with a representation rule that has a custom geometric effect or custom marker placement. Custom geometric effects or marker placements in representation rules are not supported. The rule with the problem is indicated by the <value> parameter.
Solutions
Change your representation rule to use geometric effects and marker placement provided by ArcGIS Pro.
In the Contents pane, right-click the layer and click Symbology
. In the Symbology pane, edit the representation symbology properties of the layer.Remove the layer from the map.
In the Contents pane, right-click the layer and click Remove
.
More information
Representations provide advanced capabilities for symbolizing your data. ArcGIS Pro includes a variety of geometric effects and marker placements that meet most common cartographic specifications.