When trying to establish unique symbols for a polygon layer in ArcGIS Online MapViewer I received an error Warning: "The layer is not providing enough information to change the drawing style". The unique symbols work for the points and lines layers but not for the polygon layer.
Can you share the map & layer? You can pop it into a group and invite russell_jsapi to it and I can take a look.
Ok, I've invited you to a group.
It looks like the layer does not have any features when I query it or load the table.
That's right, neither do the points or lines but I can still change their symbology. I'm trying to set it up for data collection in Field Maps app.