Error in console
Failed to call hook 'OnEntityDeath' on plugin 'PlayerChallenges v2.0.52' (NullReferenceException: Object reference not set to an instance of an object.)
  at Oxide.Plugins.PlayerChallenges.OnEntityDeath (BaseCombatEntity entity, HitInfo info) [0x00375] in <e3c7bcacb084453589fd822cecd888cc>:0
Failed to call hook 'OnEntityDeath' on plugin 'PlayerChallenges v2.0.52' (NullReferenceException: Object reference not set to an instance of an object.)
  at Oxide.Plugins.PlayerChallenges.OnEntityDeath (BaseCombatEntity entity, HitInfo info) [0x00375] in <e3c7bcacb084453589fd822cecd888cc>:0
Failed to call hook 'OnEntityDeath' on plugin 'PlayerChallenges v2.0.52' (NullReferenceException: Object reference not set to an instance of an object.)
  at Oxide.Plugins.PlayerChallenges.OnEntityDeath (BaseCombatEntity entity, HitInfo info) [0x00375] in <e3c7bcacb084453589fd822cecd888cc>:0

same here

Failed to call hook 'OnEntityDeath' on plugin 'PlayerChallenges v2.0.52' (NullReferenceException: Object reference not set to an instance of an object.) at Oxide.Plugins.PlayerChallenges.OnEntityDeath (BaseCombatEntity entity, HitInfo info) [0x00375] in <0cbb22ac21844eeabdeab6ce2ecfd5c4>:0
at Oxide.Plugins.PlayerChallenges.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00e88] in <0cbb22ac21844eeabdeab6ce2ecfd5c4>:0
at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <9c80d821d00a44c9a24497c73ad2d20d>:0
at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000de] in :0
at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in :0

Calling kill - but already IsDestroyed!? switch

Failed to call hook 'OnEntityDeath' on plugin 'PlayerChallenges v2.0.52' (NullReferenceException: Object reference not set to an instance of an object.) at Oxide.Plugins.PlayerChallenges.OnEntityDeath (BaseCombatEntity entity, HitInfo info) [0x00375] in <0cbb22ac21844eeabdeab6ce2ecfd5c4>:0
at Oxide.Plugins.PlayerChallenges.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00e88] in <0cbb22ac21844eeabdeab6ce2ecfd5c4>:0
at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <9c80d821d00a44c9a24497c73ad2d20d>:0
at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000de] in :0
at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in :0

Calling kill - but already IsDestroyed!? switch

Failed to call hook 'OnEntityDeath' on plugin 'PlayerChallenges v2.0.52' (NullReferenceException: Object reference not set to an instance of an object.) at Oxide.Plugins.PlayerChallenges.OnEntityDeath (BaseCombatEntity entity, HitInfo info) [0x00375] in <0cbb22ac21844eeabdeab6ce2ecfd5c4>:0
at Oxide.Plugins.PlayerChallenges.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00e88] in <0cbb22ac21844eeabdeab6ce2ecfd5c4>:0
at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <9c80d821d00a44c9a24497c73ad2d20d>:0
at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000de] in :0
at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in :0