Program: 10516
Project: 10516
Buggy source:
@EventHandler public void locationTrigger(PlayerMoveEvent event){
  if (event.getTo().getBlock().equals(event.getFrom().getBlock()))   return;
  ScriptHelper sE=plugin.getScriptEngine().helper;
  if (!plugin.bookmarks.getLocationTriggerList().isEmpty()) {
    boolean hasLocation=false;
    for (    Location theLocation : plugin.bookmarks.getLocationTriggerList().keySet()) {
      if (plugin.bookmarks.checkLocation(event.getPlayer(),theLocation,plugin.settings.LocationTriggerRangeInBlocks())) {
        hasLocation=true;
        DenizenNPC theDenizen=null;
        String locationTriggered=plugin.bookmarks.getLocationTriggerList().get(theLocation).split("String_Node_Str")[2];
        if (plugin.debugMode)         plugin.getLogger().info("String_Node_Str" + locationTriggered);
        if (plugin.bookmarks.getLocationTriggerList().get(theLocation).contains("String_Node_Str"))         theDenizen=plugin.getDenizenNPCRegistry().getDenizen(CitizensAPI.getNPCRegistry().getById(Integer.valueOf(plugin.bookmarks.getLocationTriggerList().get(theLocation).split("String_Node_Str")[1])));
 else         if (plugin.bookmarks.getLocationTriggerList().get(theLocation).contains("String_Node_Str")) {
          List<DenizenNPC> denizenList=new ArrayList<DenizenNPC>();
          for (          DenizenNPC npc : plugin.getDenizenNPCRegistry().getDenizens().values()) {
            if (npc.getName().equals(plugin.bookmarks.getLocationTriggerList().get(theLocation).split("String_Node_Str")[1])) {
              denizenList.add(npc);
              theDenizen=npc;
            }
          }
          for (          DenizenNPC npc : denizenList) {
            if (npc.getEntity() == null)             continue;
            if (npc.getEntity().getLocation().distance(event.getPlayer().getLocation()) < theDenizen.getEntity().getLocation().distance(event.getPlayer().getLocation()))             theDenizen=npc;
          }
        }
        if (theDenizen == null)         return;
        if (theDenizen.getCitizensEntity().getTrait(DenizenTrait.class).triggerIsEnabled("String_Node_Str")) {
          if (event.getPlayer().hasMetadata("String_Node_Str")) {
            if (locationTriggered.equals(event.getPlayer().getMetadata("String_Node_Str").get(0).asString()))             return;
            event.getPlayer().setMetadata("String_Node_Str",new FixedMetadataValue(plugin,locationTriggered));
            if (plugin.debugMode)             plugin.getLogger().log(Level.INFO,"String_Node_Str" + event.getPlayer().getMetadata("String_Node_Str").get(0).asString() + "String_Node_Str");
            if (theDenizen.IsInteractable(triggerName,event.getPlayer())) {
              sE.setCooldown(theDenizen,LocationTrigger.class,plugin.settings.DefaultLocationCooldown());
              parseLocationTrigger(theDenizen,event.getPlayer(),locationTriggered);
            }
          }
 else {
            event.getPlayer().setMetadata("String_Node_Str",new FixedMetadataValue(plugin,locationTriggered));
            if (plugin.debugMode)             plugin.getLogger().log(Level.INFO,"String_Node_Str" + event.getPlayer().getMetadata("String_Node_Str").get(0).asString() + "String_Node_Str");
            if (theDenizen.IsInteractable(triggerName,event.getPlayer())) {
              sE.setCooldown(theDenizen,LocationTrigger.class,plugin.settings.DefaultLocationCooldown());
              parseLocationTrigger(theDenizen,event.getPlayer(),locationTriggered);
            }
          }
        }
      }
    }
    if (!hasLocation) {
      if (event.getPlayer().hasMetadata("String_Node_Str"))       event.getPlayer().removeMetadata("String_Node_Str",plugin);
    }
  }
}

Fixed version (ground truth):
@EventHandler public void locationTrigger(PlayerMoveEvent event){
  if (event.getTo().getBlock().equals(event.getFrom().getBlock()))   return;
  ScriptHelper sE=plugin.getScriptEngine().helper;
  if (!plugin.bookmarks.getLocationTriggerList().isEmpty()) {
    boolean hasLocation=false;
    for (    Location theLocation : plugin.bookmarks.getLocationTriggerList().keySet()) {
      if (plugin.bookmarks.checkLocation(event.getPlayer(),theLocation,plugin.settings.LocationTriggerRangeInBlocks())) {
        hasLocation=true;
        DenizenNPC theDenizen=null;
        String locationTriggered=plugin.bookmarks.getLocationTriggerList().get(theLocation).split("String_Node_Str")[2];
        if (plugin.debugMode)         plugin.getLogger().info("String_Node_Str" + event.getPlayer().getName() + "String_Node_Str"+ locationTriggered+ "String_Node_Str");
        if (plugin.bookmarks.getLocationTriggerList().get(theLocation).contains("String_Node_Str"))         theDenizen=plugin.getDenizenNPCRegistry().getDenizen(CitizensAPI.getNPCRegistry().getById(Integer.valueOf(plugin.bookmarks.getLocationTriggerList().get(theLocation).split("String_Node_Str")[1])));
 else         if (plugin.bookmarks.getLocationTriggerList().get(theLocation).contains("String_Node_Str")) {
          List<DenizenNPC> denizenList=new ArrayList<DenizenNPC>();
          for (          DenizenNPC npc : plugin.getDenizenNPCRegistry().getDenizens().values()) {
            if (npc.getName().equals(plugin.bookmarks.getLocationTriggerList().get(theLocation).split("String_Node_Str")[1])) {
              denizenList.add(npc);
              theDenizen=npc;
            }
          }
          for (          DenizenNPC npc : denizenList) {
            if (npc.getEntity() == null)             continue;
            if (npc.getEntity().getLocation().distance(event.getPlayer().getLocation()) < theDenizen.getEntity().getLocation().distance(event.getPlayer().getLocation()))             theDenizen=npc;
          }
        }
        if (theDenizen == null)         return;
        if (theDenizen.getCitizensEntity().getTrait(DenizenTrait.class).triggerIsEnabled("String_Node_Str")) {
          if (event.getPlayer().hasMetadata("String_Node_Str")) {
            if (locationTriggered.equals(event.getPlayer().getMetadata("String_Node_Str").get(0).asString()))             return;
            event.getPlayer().setMetadata("String_Node_Str",new FixedMetadataValue(plugin,locationTriggered));
            if (plugin.debugMode)             plugin.getLogger().log(Level.INFO,"String_Node_Str" + event.getPlayer().getMetadata("String_Node_Str").get(0).asString() + "String_Node_Str");
            if (theDenizen.IsInteractable(triggerName,event.getPlayer())) {
              sE.setCooldown(theDenizen,LocationTrigger.class,plugin.settings.DefaultLocationCooldown());
              parseLocationTrigger(theDenizen,event.getPlayer(),locationTriggered);
            }
          }
 else {
            event.getPlayer().setMetadata("String_Node_Str",new FixedMetadataValue(plugin,locationTriggered));
            if (plugin.debugMode)             plugin.getLogger().log(Level.INFO,"String_Node_Str" + event.getPlayer().getMetadata("String_Node_Str").get(0).asString() + "String_Node_Str");
            if (theDenizen.IsInteractable(triggerName,event.getPlayer())) {
              sE.setCooldown(theDenizen,LocationTrigger.class,plugin.settings.DefaultLocationCooldown());
              parseLocationTrigger(theDenizen,event.getPlayer(),locationTriggered);
            }
          }
        }
      }
    }
    if (!hasLocation) {
      if (event.getPlayer().hasMetadata("String_Node_Str"))       event.getPlayer().removeMetadata("String_Node_Str",plugin);
    }
  }
}