Program: 38768
Project: 38768
Buggy source:
@EventHandler(priority=EventPriority.LOW) public void playerInteract(PlayerInteractEvent event){
  if (event.getAction() == Action.RIGHT_CLICK_BLOCK && event.getMaterial() == Material.FLINT_AND_STEEL) {
    this.plugin.log(Level.FINER,"String_Node_Str" + LocationManipulation.strCoordsRaw(event.getClickedBlock().getLocation()));
    PortalPlayerSession ps=this.plugin.getPortalSession(event.getPlayer());
    Location translatedLocation=this.getTranslatedLocation(event.getClickedBlock(),event.getBlockFace());
    if (!portalManager.isPortal(translatedLocation)) {
      return;
    }
    MVPortal portal=portalManager.isPortal(event.getPlayer(),translatedLocation);
    if (event.getItem() == null) {
      return;
    }
    if (!this.plugin.getCore().getMVPerms().hasPermission(event.getPlayer(),"String_Node_Str",true)) {
      return;
    }
    Material inHand=event.getItem().getType();
    if (portal != null) {
      this.plugin.log(Level.FINER,"String_Node_Str");
      this.plugin.log(Level.FINER,"String_Node_Str" + event.getClickedBlock() + "String_Node_Str"+ event.getClickedBlock().getType());
      this.plugin.log(Level.FINER,"String_Node_Str" + event.getPlayer().getWorld().getBlockAt(translatedLocation) + "String_Node_Str"+ event.getPlayer().getWorld().getBlockAt(translatedLocation).getType());
      this.plugin.log(Level.FINER,"String_Node_Str" + inHand);
      if (ps.isDebugModeOn()) {
        ps.showDebugInfo(portal);
        event.setCancelled(true);
      }
 else {
        Material fillMaterial=Material.PORTAL;
        if (translatedLocation.getWorld().getBlockAt(translatedLocation).getType() == Material.PORTAL) {
          fillMaterial=Material.AIR;
        }
        this.plugin.log(Level.FINER,"String_Node_Str" + fillMaterial);
        event.setCancelled(this.filler.fillRegion(portal.getLocation().getRegion(),translatedLocation,fillMaterial,event.getPlayer()));
      }
    }
    return;
  }
  int itemType=this.plugin.getMainConfig().getInt("String_Node_Str",MultiversePortals.DEFAULT_WAND);
  if (this.plugin.getWEAPI() != null || event.getPlayer().getItemInHand().getTypeId() != itemType || !this.plugin.getCore().getMVPerms().hasPermission(event.getPlayer(),"String_Node_Str",true)) {
    return;
  }
  if (event.getAction() == Action.LEFT_CLICK_BLOCK) {
    MultiverseWorld world=this.plugin.getCore().getMVWorldManager().getMVWorld(event.getPlayer().getWorld().getName());
    event.setCancelled(this.plugin.getPortalSession(event.getPlayer()).setLeftClickSelection(event.getClickedBlock().getLocation().toVector(),world));
  }
 else   if (event.getAction() == Action.RIGHT_CLICK_BLOCK) {
    MultiverseWorld world=this.plugin.getCore().getMVWorldManager().getMVWorld(event.getPlayer().getWorld().getName());
    event.setCancelled(this.plugin.getPortalSession(event.getPlayer()).setRightClickSelection(event.getClickedBlock().getLocation().toVector(),world));
  }
}

Fixed version (ground truth):
@EventHandler(priority=EventPriority.LOW) public void playerInteract(PlayerInteractEvent event){
  if (event.getAction() == Action.RIGHT_CLICK_BLOCK && event.getMaterial() == Material.FLINT_AND_STEEL) {
    this.plugin.log(Level.FINER,"String_Node_Str" + this.plugin.getCore().getLocationManipulation().strCoordsRaw(event.getClickedBlock().getLocation()));
    PortalPlayerSession ps=this.plugin.getPortalSession(event.getPlayer());
    Location translatedLocation=this.getTranslatedLocation(event.getClickedBlock(),event.getBlockFace());
    if (!portalManager.isPortal(translatedLocation)) {
      return;
    }
    MVPortal portal=portalManager.isPortal(event.getPlayer(),translatedLocation);
    if (event.getItem() == null) {
      return;
    }
    if (!this.plugin.getCore().getMVPerms().hasPermission(event.getPlayer(),"String_Node_Str",true)) {
      return;
    }
    Material inHand=event.getItem().getType();
    if (portal != null) {
      this.plugin.log(Level.FINER,"String_Node_Str");
      this.plugin.log(Level.FINER,"String_Node_Str" + event.getClickedBlock() + "String_Node_Str"+ event.getClickedBlock().getType());
      this.plugin.log(Level.FINER,"String_Node_Str" + event.getPlayer().getWorld().getBlockAt(translatedLocation) + "String_Node_Str"+ event.getPlayer().getWorld().getBlockAt(translatedLocation).getType());
      this.plugin.log(Level.FINER,"String_Node_Str" + inHand);
      if (ps.isDebugModeOn()) {
        ps.showDebugInfo(portal);
        event.setCancelled(true);
      }
 else {
        Material fillMaterial=Material.PORTAL;
        if (translatedLocation.getWorld().getBlockAt(translatedLocation).getType() == Material.PORTAL) {
          fillMaterial=Material.AIR;
        }
        this.plugin.log(Level.FINER,"String_Node_Str" + fillMaterial);
        event.setCancelled(this.filler.fillRegion(portal.getLocation().getRegion(),translatedLocation,fillMaterial,event.getPlayer()));
      }
    }
    return;
  }
  int itemType=this.plugin.getMainConfig().getInt("String_Node_Str",MultiversePortals.DEFAULT_WAND);
  if (this.plugin.getWEAPI() != null || event.getPlayer().getItemInHand().getTypeId() != itemType || !this.plugin.getCore().getMVPerms().hasPermission(event.getPlayer(),"String_Node_Str",true)) {
    return;
  }
  if (event.getAction() == Action.LEFT_CLICK_BLOCK) {
    MultiverseWorld world=this.plugin.getCore().getMVWorldManager().getMVWorld(event.getPlayer().getWorld().getName());
    event.setCancelled(this.plugin.getPortalSession(event.getPlayer()).setLeftClickSelection(event.getClickedBlock().getLocation().toVector(),world));
  }
 else   if (event.getAction() == Action.RIGHT_CLICK_BLOCK) {
    MultiverseWorld world=this.plugin.getCore().getMVWorldManager().getMVWorld(event.getPlayer().getWorld().getName());
    event.setCancelled(this.plugin.getPortalSession(event.getPlayer()).setRightClickSelection(event.getClickedBlock().getLocation().toVector(),world));
  }
}