14:22:07: ERROR[main]: ERROR: An unhandled exception occurred: ServerError: LuaE
rror: error: /usr/share/minetest/builtin/vector.lua:44: attempt to perform arithmetic on field 'x' (a nil value)
14:22:07: ERROR[main]: stack traceback:

In thread 7fd6ff50f780:
/home/vanessa/Minetest-related/minetest_core/src/main.cpp:1778: int main(int, char**): Assertion '0' failed.
Debug stacks:
DEBUG STACK FOR THREAD 7fd6ff50f780:
#0  int main(int, char**)
(Leftover data: #1  Dedicated server branch)
(Leftover data: #2  virtual void ServerMap::save(ModifiedState))
(Leftover data: #3  virtual void ServerMap::saveBlock(MapBlock*))
(Leftover data: #4  void ItemStack::serialize(std::ostream&) const)