I'm getting this in console

 Failed to call hook 'OnItemCraft' on plugin 'InstantCraft v2.1.5' (NullReferenceException: Object reference not set to an instance of an object)
  at Item.OnChanged () [0x0001d] in <c8f52207be534df0a09963fbe837cda2>:0 
  at Item.MarkDirty () [0x00000] in <c8f52207be534df0a09963fbe837cda2>:0 
  at Item.set_maxCondition (System.Single value) [0x00029] in <c8f52207be534df0a09963fbe837cda2>:0 
  at Item.Initialize (ItemDefinition template) [0x00010] in <c8f52207be534df0a09963fbe837cda2>:0 
  at ItemManager.Create (ItemDefinition template, System.Int32 iAmount, System.UInt64 skin) [0x00065] in <c8f52207be534df0a09963fbe837cda2>:0 
  at Oxide.Plugins.InstantCraft.GiveItem (BasePlayer player, ItemCraftTask task, ItemDefinition def, System.Collections.Generic.List`1[T] stacks, System.Int32 taskSkinID) [0x00057] in <74617a582726486e8321a558eab05897>:0 
  at Oxide.Plugins.InstantCraft.OnCraft (ItemCraftTask task) [0x0011b] in <74617a582726486e8321a558eab05897>:0 
  at Oxide.Plugins.InstantCraft.OnItemCraft (ItemCraftTask item) [0x00000] in <74617a582726486e8321a558eab05897>:0 
  at Oxide.Plugins.InstantCraft.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00126] in <74617a582726486e8321a558eab05897>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <31122a27a2414cd799150f8677cf39d4>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <c2afd8354b8b4f3ca451cf5a1aa111c3>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <c2afd8354b8b4f3ca451cf5a1aa111c3>:0

I'm also running the crafting perk ZLevels. I just now started allowing instacraft during purge. But I haven't heard anyone say something about instant craft failing.

Getting this now

| Failed to call hook 'OnItemCraft' on plugin 'InstantCraft v2.1.5' (NullReferenceException: Object reference not set to an instance of an object)
  at Item.OnChanged () [0x0001d] in <622100108423464eb70d44bb94c0f765>:0 
  at Item.MarkDirty () [0x00000] in <622100108423464eb70d44bb94c0f765>:0 
  at Item.set_maxCondition (System.Single value) [0x00029] in <622100108423464eb70d44bb94c0f765>:0 
  at Item.Initialize (ItemDefinition template) [0x00010] in <622100108423464eb70d44bb94c0f765>:0 
  at ItemManager.Create (ItemDefinition template, System.Int32 iAmount, System.UInt64 skin) [0x00065] in <622100108423464eb70d44bb94c0f765>:0 
  at Oxide.Plugins.InstantCraft.GiveItem (BasePlayer player, ItemCraftTask task, ItemDefinition def, System.Collections.Generic.List`1[T] stacks, System.Int32 taskSkinID) [0x00057] in <7e8ebb893a514b9e8a9fc6fec5fd685a>:0 
  at Oxide.Plugins.InstantCraft.OnCraft (ItemCraftTask task) [0x0011b] in <7e8ebb893a514b9e8a9fc6fec5fd685a>:0 
  at Oxide.Plugins.InstantCraft.OnItemCraft (ItemCraftTask item) [0x00000] in <7e8ebb893a514b9e8a9fc6fec5fd685a>:0 
  at Oxide.Plugins.InstantCraft.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x00126] in <7e8ebb893a514b9e8a9fc6fec5fd685a>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <31122a27a2414cd799150f8677cf39d4>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <0fbce81d88d64454b3e7abb24df7026b>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <0fbce81d88d64454b3e7abb24df7026b>:0

Still happening

thepiercedweirdo

Still happening

Someone upper noticed that its because of ZLevelsRemastered. You can try to unload all plugins that affecting craft and give a try