Gravity First Load Test

Exception occured: System.NullReferenceException: Object reference not set to an instance of an object.
   at IndustrialAutomaton.Gravity.IndustrialAutomaton_Gravity.grabEntities()
   at IndustrialAutomaton.Gravity.IndustrialAutomaton_Gravity.UpdateBeforeSimulation10()
   at VRage.Game.Components.MyGameLogicComponent.VRage.Game.Entity.EntityComponents.Interfaces.IMyGameLogicComponent.UpdateBeforeSimulation10(Boolean entityUpdate)
   at Sandbox.Game.Entities.MyCompositeGameLogicComponent.VRage.Game.Entity.EntityComponents.Interfaces.IMyGameLogicComponent.UpdateBeforeSimulation10(Boolean entityUpdate)
   at Sandbox.Game.Entities.MyCubeBlock.UpdateBeforeSimulation10()
   at Sandbox.Game.Entities.MyEntities.<UpdateBeforeSimulation>b__8(MyEntity x)
   at VRage.Collections.MyDistributedUpdater`2.Iterate(Action`1 p)
   at Sandbox.Game.Entities.MyEntities.UpdateBeforeSimulation()
   at Sandbox.Game.World.MySector.UpdateBeforeSimulation()
   at Sandbox.Game.World.MySession.UpdateComponents()
   at Sandbox.Game.World.MySession.Update(MyTimeSpan updateTime)
   at Sandbox.MySandboxGame.Update()
   at Sandbox.Engine.Platform.Game.UpdateInternal()
   at Sandbox.Engine.Platform.Game.RunSingleFrame()
   at Sandbox.Engine.Platform.FixedLoop.<>c__DisplayClass1.<Run>b__0()
   at Sandbox.Engine.Platform.GenericLoop.Run(VoidAction tickCallback)
   at Sandbox.Engine.Platform.Game.RunLoop()
   at Sandbox.MySandboxGame.Run(Boolean customRenderLoop, Action disposeSplashScreen)
   at SpaceEngineers.MyProgram.Main(String[] args)