I am trying to add a halo around symbols i have mapped in ArcMap 10.4 to make them more visible on the map. The symbols are plotted as points. I went to the shapefiles properties -> symbology tab -> clicked on symbol -> edit symbol -> mask tab -> changed "none" to "halo" and set halo to be 5 in size. When i apply this and press okay, it does nothing to the symbol. This is happening with my other shapefiles as well.
Am i doing something wrong?