Failed to call hook 'OnEntityDeath' on plugin 'PlayerChallenges v2.0.48' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.PlayerChallenges.OnEntityDeath (BaseCombatEntity entity, HitInfo info) [0x003cb] in <95c68acfb0b24e14918d1fedbc1dc02a>:0 
  at Oxide.Plugins.PlayerChallenges.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00e80] in <95c68acfb0b24e14918d1fedbc1dc02a>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <09575a60985045248bcb43b20faeeb99>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <d5f57e12edfe4fa0b5c5dbdd9b51eff8>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <d5f57e12edfe4fa0b5c5dbdd9b51eff8>:0 

Also getting this error as well on server start up

Failed to call hook 'OnServerSave' on plugin 'PlayerChallenges v2.0.48' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.PlayerChallenges.SaveData () [0x00000] in <8fb9bd4731884002b112dacb2e817802>:0 
  at Oxide.Plugins.PlayerChallenges.OnServerSave () [0x00000] in <8fb9bd4731884002b112dacb2e817802>:0 
  at Oxide.Plugins.PlayerChallenges.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00acc] in <8fb9bd4731884002b112dacb2e817802>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <09575a60985045248bcb43b20faeeb99>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <d5f57e12edfe4fa0b5c5dbdd9b51eff8>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <d5f57e12edfe4fa0b5c5dbdd9b51eff8>:0 
Failed to call hook 'OnServerSave' on plugin 'RestoreUponDeath v0.5.0' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.RestoreUponDeath.SaveData () [0x00000] in <8fb9bd4731884002b112dacb2e817802>:0 
  at Oxide.Plugins.RestoreUponDeath.OnServerSave () [0x00000] in <8fb9bd4731884002b112dacb2e817802>:0 
  at Oxide.Plugins.RestoreUponDeath.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00126] in <8fb9bd4731884002b112dacb2e817802>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <09575a60985045248bcb43b20faeeb99>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <d5f57e12edfe4fa0b5c5dbdd9b51eff8>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <d5f57e12edfe4fa0b5c5dbdd9b51eff8>:0 ​