the plasma that is shot out of the banshee doesn't have a model so you have to swap the projectiles so that the banshee shoots something that has a model, the use the plugin to swap the models
Banshee's fuel rod gun model is NaN, but you can still use Deadly Shadow's plugin to go to scenery\a50_rock_large\rock_large take its model # and paste it into the NaN model number for the banshees fuel rod. Then save.You won't get an exception error or anything when you shoot.