when server starting, i get this:

Failed to call hook 'Unload' on plugin 'ZoneManager v3.0.15' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.ZoneManager.DestroyUpdateBehaviour () [0x00000] in <7e9789df50cf425385a7cfe24b89adb6>:0
  at Oxide.Plugins.ZoneManager.Unload () [0x00000] in <7e9789df50cf425385a7cfe24b89adb6>:0
  at Oxide.Plugins.ZoneManager.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00db4] in <7e9789df50cf425385a7cfe24b89adb6>:0
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <d09a1f46ca2f4432811bcfe45ad13c7b>:0
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <cf88a28c7fb44d36890d85a78331cc9d>:0
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <cf88a28c7fb44d36890d85a78331cc9d>:0

> version
Protocol: 2256.198.1
Build Date: 09/03/2020 10:58:29
Unity Version: 2019.3.5f1
Changeset: 54308
Branch: release
> o.version
Oxide.Rust Version: 2.0.4732

09:54 [Error] Failed to call hook 'Unload' on plugin 'ZoneManager v3.0.16' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.ZoneManager.DestroyUpdateBehaviour () [0x00000] in <70b215daa9264c17af527f6a3cc62eba>:0 
  at Oxide.Plugins.ZoneManager.Unload () [0x00000] in <70b215daa9264c17af527f6a3cc62eba>:0 
  at Oxide.Plugins.ZoneManager.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00db4] in <70b215daa9264c17af527f6a3cc62eba>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <80b90e8213db44b29ec2d4111764172c>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <ec05e0208c9149bba43236ca58fea105>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <ec05e0208c9149bba43236ca58fea105>:0

I have a few of my plugins reload about twice a day automatically.  Zone Manager is one of them.  I get this error each time it gets reloaded.  Just, throwing that out there.