Program: 33834
Project: 33834
Buggy source:
/** 
 * This handles non-player portal use Currently disables portal use by entities
 * @param event
 */
@EventHandler(priority=EventPriority.NORMAL,ignoreCancelled=true) public void onEntityPortal(EntityPortalEvent event){
  if (DEBUG)   plugin.getLogger().info("String_Node_Str" + event.getFrom().getBlock().getType());
  if (!Settings.createNether || ASkyBlock.getNetherWorld() == null) {
    return;
  }
  if (event.getEntity() == null) {
    return;
  }
  if (event.getFrom() != null && event.getFrom().getBlock().getType().equals(Material.ENDER_PORTAL)) {
    event.setCancelled(true);
    if (!event.getFrom().getWorld().getEnvironment().equals(Environment.THE_END)) {
      if (plugin.getServer().getWorld(Settings.worldName + "String_Node_Str") != null) {
        Location end_place=plugin.getServer().getWorld(Settings.worldName + "String_Node_Str").getSpawnLocation();
        event.getEntity().teleport(end_place);
        if (DEBUG)         plugin.getLogger().info("String_Node_Str" + event.getEntityType() + "String_Node_Str"+ end_place);
        return;
      }
    }
    return;
  }
  Location currentLocation=event.getFrom().clone();
  String currentWorld=currentLocation.getWorld().getName();
  if (!currentWorld.equalsIgnoreCase(Settings.worldName) && !currentWorld.equalsIgnoreCase(Settings.worldName + "String_Node_Str")) {
    return;
  }
  if (!Settings.newNether) {
    event.setCancelled(true);
    return;
  }
  Location dest=event.getFrom().toVector().toLocation(ASkyBlock.getIslandWorld());
  if (event.getFrom().getWorld().getEnvironment().equals(Environment.NORMAL)) {
    dest=event.getFrom().toVector().toLocation(ASkyBlock.getNetherWorld());
  }
  if (event.getEntity() instanceof Vehicle) {
    Vehicle vehicle=(Vehicle)event.getEntity();
    vehicle.eject();
  }
  new SafeSpotTeleport(plugin,event.getEntity(),dest);
  event.setCancelled(true);
}

Fixed version (ground truth):
/** 
 * This handles non-player portal use Currently disables portal use by entities
 * @param event
 */
@EventHandler(priority=EventPriority.NORMAL,ignoreCancelled=true) public void onEntityPortal(EntityPortalEvent event){
  if (DEBUG)   plugin.getLogger().info("String_Node_Str" + event.getFrom().getBlock().getType());
  if (!Settings.createNether || ASkyBlock.getNetherWorld() == null) {
    if (DEBUG)     plugin.getLogger().info("String_Node_Str" + Settings.createNether + "String_Node_Str"+ (ASkyBlock.getNetherWorld() == null ? "String_Node_Str" : "String_Node_Str"));
    return;
  }
  if (event.getEntity() == null) {
    if (DEBUG)     plugin.getLogger().info("String_Node_Str");
    return;
  }
  if (event.getFrom() != null && event.getFrom().getBlock().getType().equals(Material.ENDER_PORTAL)) {
    event.setCancelled(true);
    if (!event.getFrom().getWorld().getEnvironment().equals(Environment.THE_END)) {
      if (plugin.getServer().getWorld(Settings.worldName + "String_Node_Str") != null) {
        Location end_place=plugin.getServer().getWorld(Settings.worldName + "String_Node_Str").getSpawnLocation();
        event.getEntity().teleport(end_place);
        if (DEBUG)         plugin.getLogger().info("String_Node_Str" + event.getEntityType() + "String_Node_Str"+ end_place);
        return;
      }
    }
    return;
  }
  Location currentLocation=event.getFrom().clone();
  String currentWorld=currentLocation.getWorld().getName();
  if (!currentWorld.equalsIgnoreCase(Settings.worldName) && !currentWorld.equalsIgnoreCase(Settings.worldName + "String_Node_Str")) {
    if (DEBUG)     plugin.getLogger().info("String_Node_Str");
    return;
  }
  if (!Settings.newNether) {
    if (DEBUG)     plugin.getLogger().info("String_Node_Str");
    event.setCancelled(true);
    return;
  }
  Location dest=event.getFrom().toVector().toLocation(ASkyBlock.getIslandWorld());
  if (event.getFrom().getWorld().getEnvironment().equals(Environment.NORMAL)) {
    dest=event.getFrom().toVector().toLocation(ASkyBlock.getNetherWorld());
  }
  if (event.getEntity() instanceof Vehicle) {
    Vehicle vehicle=(Vehicle)event.getEntity();
    vehicle.eject();
  }
  new SafeSpotTeleport(plugin,event.getEntity(),dest);
  event.setCancelled(true);
}