“The selected webmap does not contain a valid layer to use. Please add an editable FeatureLayer into your webmap to continue." error on using a hosted feature layer view to configure a GeoForm application.
It is expected that the feature layer shows in Geoform versus the view because when a view is edited, it is actually the underlying feature layer data that gets edited. You can see that for confirmation by looking at the REST endpoint > Layers property of the view.