Server crash

[ghost]

minetest version 5.4
Paleotest update at commit 7f3c5fa

2021-03-27 20:44:57: ERROR[Main]: ServerError: AsyncErr: ServerThread::run Lua: Runtime error from mod '??' in callback luaentity_Step(): Expecting itemstack, itemstring, table or nil
2021-03-27 20:44:57: ERROR[Main]: stack traceback:
2021-03-27 20:44:57: ERROR[Main]: [C]: in function 'set_stack'
2021-03-27 20:44:57: ERROR[Main]: /home/minetest/minetest/bin/../mods/paleotest/feeders.lua:109: in function 'on_feed'
2021-03-27 20:44:57: ERROR[Main]: /home/minetest/minetest/bin/../mods/paleotest/api/hq_lq.lua:170: in function 'eat_from_feeder'
2021-03-27 20:44:57: ERROR[Main]: /home/minetest/minetest/bin/../mods/paleotest/api/hq_lq.lua:215: in function 'func'
2021-03-27 20:44:57: ERROR[Main]: /home/minetest/minetest/bin/../mods/mobkit/init.lua:621: in function 'execute_queues'
2021-03-27 20:44:57: ERROR[Main]: /home/minetest/minetest/bin/../mods/mobkit/init.lua:848: in function 'stepfunc'
2021-03-27 20:44:57: ERROR[Main]: /home/minetest/minetest/bin/../mods/paleotest/api/api.lua:88: in function 'old_step'
2021-03-27 20:44:57: ERROR[Main]: .../minetest/minetest/bin/../mods/paleotest/api/register.lua:53: in function <.../minetest/minetest/bin/../mods/paleotest/api/register.lua:52>