Null Object Reference Error 2

_error.txt 2

SystemData
{
  OS : Windows 10 (Pre-release)
  RAM: 12469292 KB (11.89 GB)
  CPU: Intel(R) Core(TM) i7-4720HQ CPU @ 2.60GHz
  GPU: NVIDIA GeForce GTX 950MIntel(R) HD Graphics 4600, driver v. 22.21.13.847620.19.15.4549
}
--------------------------------------
game id:	DQ1
filename:	DefendersQuest
package:	com.leveluplabs.defq1
version:	2.2.0
tdrpg v:	2.1.6
session ID:	DQ1_2017-12-30_22'19'17
started:	2017-12-30 22:19:17
--------------------------------------
crashed:	2017-12-30 22:26:21
duration:	00:07:03
error:		UNCAUGHT ERROR : Null Object Reference
stack:
flixel.FlxObject.update (flixel/FlxObject.hx line 625)
flixel.FlxSprite.update (flixel/FlxSprite.hx line 596)
com.leveluplabs.tdrpg.TDRPGEntitySprite.update (com/leveluplabs/tdrpg/TDRPGEntitySprite.hx line 100)
com.leveluplabs.tdrpg.CreatureSprite.updateEffectGroup (com/leveluplabs/tdrpg/CreatureSprite.hx line 1877)
com.leveluplabs.tdrpg.CreatureSprite.updateEffects (com/leveluplabs/tdrpg/CreatureSprite.hx line 1842)
com.leveluplabs.tdrpg.EnemySprite.updateEffects (com/leveluplabs/tdrpg/EnemySprite.hx line 2165)
com.leveluplabs.tdrpg.CreatureSprite.updateFromModelEvenIfDying (com/leveluplabs/tdrpg/CreatureSprite.hx line 1901)
com.leveluplabs.tdrpg.BattleModel.updateEnemies (com/leveluplabs/tdrpg/BattleModel.hx line 3572)
com.leveluplabs.tdrpg.BattleModel.doUpdate (com/leveluplabs/tdrpg/BattleModel.hx line 2023)
com.leveluplabs.tdrpg.BattleModel.update (com/leveluplabs/tdrpg/BattleModel.hx line 1597)
com.leveluplabs.tdrpg.State_Battle.battleUpdate (com/leveluplabs/tdrpg/State_Battle.hx line 1849)
com.leveluplabs.tdrpg.State_Battle.update (com/leveluplabs/tdrpg/State_Battle.hx line 1614)
flixel.FlxState.tryUpdate (flixel/FlxState.hx line 168)
flixel.FlxGame.update (flixel/FlxGame.hx line 750)
com.leveluplabs.tdrpg.Main.update (com/leveluplabs/tdrpg/Main.hx line 2382)
flixel.FlxGame.step (flixel/FlxGame.hx line 674)
flixel.FlxGame.onEnterFrame (flixel/FlxGame.hx line 541)
openfl.events.EventDispatcher.__dispatchEvent (openfl/events/EventDispatcher.hx line 237)
openfl.display.DisplayObject.__broadcast (openfl/display/DisplayObject.hx line 255)
openfl.display.DisplayObjectContainer.__broadcast (openfl/display/DisplayObjectContainer.hx line 358)
openfl.display.Stage.render (openfl/display/Stage.hx line 761)
openfl.display.Stage.addRenderer (openfl/display/Stage.hx line 200)