Getting this issue with Raidable bases and when trying to use Zone Manager

Failed to call hook 'OnEntityKill' on plugin 'ZoneManager v3.0.23' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.ZoneManager+Zone.OnEntityExitZone (BaseEntity baseEntity, System.Boolean resetDecay, System.Boolean isDead) [0x00000] in <d5d390aa9bf04db8a3ae58647ccc7b03>:0 
  at Oxide.Plugins.ZoneManager.OnEntityKill (BaseEntity baseEntity) [0x00062] in <d5d390aa9bf04db8a3ae58647ccc7b03>:0 
  at Oxide.Plugins.ZoneManager.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00874] in <d5d390aa9bf04db8a3ae58647ccc7b03>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <e23ba2c0f246426296d81c842cbda3af>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <50629aa0e75d4126b345d8d9d64da28d>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args)