Problem: Unable to select a layer in the Search Settings section of the District Lookup widget
When configuring the District Lookup widget in Web AppBuilder for ArcGIS, selecting a layer in the Search Settings section returns the following warning message:
Please select a polygon layer which has a related point layer.
The following are three possible reasons for this issue:
The data have a one-to-many (1:M) relationship. However, the layer in the District Lookup widget only requires a one-to-one (1:1) cardinality in the relationship class. For more information, refer to the following link: District Lookup widget
There is no relationship class associated with the data layer.
The data consist of on-the-fly relates, which are not maintained once the layer is published as a feature service.