Robert,
Sorry for the late reply.
I have been using the widget for a property search. The first search always works and displays in the attribute table (both searching by Shape and Attribute work)
The second search, either by shape or attribute, generates that error message in the console and the attribute results layer will just spin.
I did notice that it does return results from inside the widget, I am not sure if that is anything definitive between your widget and the Attribute Table widget.
Just let me know. Thanks for all of your help.
EDIT: I forgot to attach the config.json for the app