Display layer data in web app attribute table

[MarkBushyeager]

I have created a web app using the ArcGIS Online Web App Builder.  I want to use the attribute table widget to access the data in the layers.  When I configure the attribute table widget, one of the layers (call it layer "A") does not show in the list, so I can't display it in the table.  However, if I open the "Layer List" widget, layer A is displayed.  I can click the dropdown button next to layer A, select "Open attribute table", and then the data displays perfectly in the attribute table widget.  Unfortunately, I can't save the web app in the configuration that displays layer A.  I can't see any difference between the properties for layer A and the other layers that I am able configure.  Any ideas?

[ZhifangWang]

Hi Mark,

Would you give some details background of the specific "layer A"? I think there must be some reasons for it does not show in configure dialog of Attribute Table widget.

However, we cannot give you any further suggestions unless we know the details of your "layer A", such as what's data source of it? Where it redirects to when you click the "description" in the context menu of Layer list widget? A map service layer or feature service layer? Is it secured? Or it's an csv layer? Can it be shown in the table of ArcGIS Online mapviewer? etc.