PictureMarkerSymbol not showing on Python API

[YingtongZhong21]

I want to draw feature layer point symbols using custom symbols. The codes are below:

traffic_accident_symbol = {"type":"esriPMS", "url":"http://static.arcgis.com/images/Symbols/Transportation/TrafficAccident.png", "contentType": "image/png", "width":20, "height":20}

map1.draw(crash, symbol=traffic_accident_symbol)

Crash is a feature layer.

Nothing shows up on the map with a white box on the upper right saying "error on updating graphics, see the browser console for more info."

Does anyone encounter the same problem? I saw using renderer solution for Java, but none for python.