08:56:41: ACTION[main]: World at [/home/ojirio/.minetest/worlds/m6]
08:56:41: ACTION[main]: Server for gameid="minetest" listening on port 30011.
creative inventory size: 176
on_newplayer
08:56:41: ACTION[ServerThread]: singleplayer joins game. List of players: singleplayer
Could not open file of texture: character.png
Loaded mesh: character.x
PNG warning: Interlace handling should be turned on when using png_read_image
PNG warning: Interlace handling should be turned on when using png_read_image
Loaded texture: /usr/share/minetest/textures/base/pack/sunrisebg.png
Font size: 8 15
08:56:49: ERROR[EmergeThread]: ERROR: An unhandled exception occurred: LuaError: error: ...minetest/games/minetest_game/mods/default/mapgen.lua:399: attempt to call field 'get_node' (a nil value)
08:56:49: ERROR[EmergeThread]: stack traceback:

In thread b2363b40:
/var/abs/local/minetest-git/src/minetest/src/emerge.cpp:473: virtual void* EmergeThread::Thread(): Assertion '0' failed.
Debug stacks:
DEBUG STACK FOR THREAD b2363b40:
#0  virtual void* EmergeThread::Thread()
(Leftover data: #1  virtual MapBlock* ServerMap::emergeBlock(v3s16, bool): p=(3,3,3), create_blank=0)
(Leftover data: #2  ServerMapSector* ServerMap::createSector(v2s16): p2d=(3,3))
DEBUG STACK FOR THREAD b2bb3b40:
#0  virtual void* MeshUpdateThread::Thread()
DEBUG STACK FOR THREAD b41fcb40:
#0  virtual void* ServerThread::Thread()
#1  void Server::AsyncRunStep()
#2  void Server::SendBlocks(float)
#3  void RemoteClient::GetNextBlocks(Server*, float, std::vector<PrioritySortedBlockTransfer>&)
(Leftover data: #4  void ItemStack::serialize(std::ostream&) const)
(Leftover data: #5  MapSector* ServerMap::loadSectorMeta(std::string, bool))
DEBUG STACK FOR THREAD b6e6e700:
#0  int main(int, char**)
(Leftover data: #1  void Client::step(float))
(Leftover data: #2  virtual void ClientEnvironment::step(float))
(Leftover data: #3  void Client::Receive())
(Leftover data: #4  void Client::ProcessData(irr::u8*, irr::u32, irr::u16))
(Leftover data: #5  void ItemStack::deSerialize(std::istream&, IItemDefManager*))
Aborted (core dumped)