Birchnutdrakebrain Error

So today my Dedicated Server crashed due to the following error. I assume this is a game issue as it's not pointing out any mod related errors. But I'll try to find and see if it's caused by any mods;

[05:32:08]: [string "scripts/brains/birchnutdrakebrain.lua"]:18: attempt to index field 'hauntable' (a nil value)
LUA ERROR stack traceback:
scripts/brains/birchnutdrakebrain.lua:18 in (field) fn (Lua) <18-18>
scripts/behaviourtree.lua:200 in (method) Visit (Lua) <199-205>
   self =
      lastresult = READY
      status = READY
      fn = function - scripts/brains/birchnutdrakebrain.lua:18
      parent = table: 5F1D2DE0
      name = Panic
scripts/behaviourtree.lua:643 in (method) Visit (Lua) <633-664>
   self =
      name = Parallel
      status = READY
      parent = table: 5F1DF220
      children = table: 5F1D9118
      lastresult = READY
   done = true
   any_done = false
   idx = 1
   child = table: 5F1D1F08
scripts/behaviourtree.lua:578 in (method) Visit (Lua) <554-610>
   self =
      lasttime = 19712.134361401
      name = Priority
      status = READY
      period = 0.25
      children = table: 5F1D2688
      lastresult = READY
   time = 19712.134361401
   do_eval = true
   oldidx = nil
   old_event = nil
   found = false
   idx = 1
   child = table: 5F1D2DE0
   should_test_anyway = nil
scripts/behaviourtree.lua:22 in (method) Update (Lua) <20-27>
   self =
      inst = 276542 - birchnutdrake (valid:true)
      root = table: 5F1DF220
scripts/brain.lua:212 in (method) OnUpdate (Lua) <205-214>
   self =
      bt = Priority - READY <READY> ()>0.00
   >Parallel - READY <READY> ()>0.00
   >   >Panic - READY <READY> ()>0.00
   >   >Panic - READY <READY> ()>0.00
   >Leash - READY <READY> ()>0.00
   >ChaseAndAttack - READY <READY> ()>0.00
   >ActionNode - READY <READY> ()>0.00

      events = table: 5F1D7610
      behaviourqueue = table: 5F1DD470
      stopped = false
      inst = 276542 - birchnutdrake (valid:true)
scripts/brain.lua:135 in (method) Update (Lua) <105-147>
   self =
      hibernaters = table: 059D2698
      updaters = table: 059D0D48
      tickwaiters = table: 059DB478
      instances = table: 059DDB88
   current_tick = 591364
   waiters = table: 5DEC0D70
   k = --brain--
sleep time: 0.00
Priority - READY <READY> ()>0.00
   >Parallel - READY <READY> ()>0.00
   >   >Panic - READY <READY> ()>0.00
   >   >Panic - READY <READY> ()>0.00
   >Leash - READY <READY> ()>0.00
   >ChaseAndAttack - READY <READY> ()>0.00
   >ActionNode - READY <READY> ()>0.00

   v = true
scripts/update.lua:222 in () ? (Lua) <149-228>
   dt = 0.033333335071802
   tick = 591364
   i = 591364

[05:32:08]: [string "scripts/brains/birchnutdrakebrain.lua"]:18: attempt to index field 'hauntable' (a nil value)
LUA ERROR stack traceback:
    scripts/brains/birchnutdrakebrain.lua:18 in (field) fn (Lua) <18-18>
    scripts/behaviourtree.lua:200 in (method) Visit (Lua) <199-205>
    scripts/behaviourtree.lua:643 in (method) Visit (Lua) <633-664>
    scripts/behaviourtree.lua:578 in (method) Visit (Lua) <554-610>
    scripts/behaviourtree.lua:22 in (method) Update (Lua) <20-27>
    scripts/brain.lua:212 in (method) OnUpdate (Lua) <205-214>
    scripts/brain.lua:135 in (method) Update (Lua) <105-147>
    scripts/update.lua:222 in () ? (Lua) <149-228>