The selection widget will hang if a point layer contains records that were unsuccessfully geocoded (contains NULL in the geometry field).
I've reached out to Esri tech support (BUG-00105003) and the developers say that it's the responsibility of the user to check data integrity before publishing.
In publishing the data in ArcMap with NULL geometry, there is no indication when analyzing the data in the publishing wizard that there is any error, warning or a problem that the data contains NULL geometry. They suggested running the "Repair Geometry" tool in desktop. However, that permanently removes records that I may not want to delete.
I understand that data integrity is important, but what would a user do if they are geocoding a table directly online using the world geocoder and end up with unmatched records? In this situation, ArcGIS Online does NOT have the ability to repair geometry.
Shouldn't we just adjust or correct the Web AppBuilder selection widget to ignore NULL geometry? There is no problem when spatially selecting in ArcMap or ArcGIS Pro when your data contains NULL geometry. Can we be consistent?
Feedback and thoughts would be appreciated.
I can't really see a straightforward solution for this issue.
One possible workaround is by applying a filter in the web map. You can't filter by geometry, but if the null geometry is expressed in other ways in the attribute table you can run a filter on those 'null-related' attributes.
This will solve your selection problem, but would still leave the user wondering what happened to their input if it was null.