Publishing a scene layer package to ArcGIS Online returns the following error in the scene viewer, "<Scene layer name> might not display as expected Symbols of type 'unknown' are not supported."
1. Symbolize the feature layer using 'Symbolize your layer by quantities' (for example, Graduated Colors or Graduated Symbols) or 'Symbolize your layer using one symbol' (Single Symbol).2. In the scene viewer, click the drop-down menu for the layer, and select Configure Layer. In the Symbols drop-down list, select Change Symbol, and click DONE.