Unity internally removes "blank" layer fields, including (currently) three internal layers, which will change the value of any layer that is added after a blank layer. Using the to/from ConcatenatedLayersMask we can get the correct functionality of the layers mask selector. (Small graphical bug: when "Everything" is selected, it will say "Mixed" because the blank layer fields will not be set.)
Unity internally removes "blank" layer fields, including (currently) three internal layers, which will change the value of any layer that is added after a blank layer. Using the to/from ConcatenatedLayersMask we can get the correct functionality of the layers mask selector. (Small graphical bug: when "Everything" is selected, it will say "Mixed" because the blank layer fields will not be set.)