2015-09-29 12:07:00: ERROR[main]: UNRECOVERABLE error occurred. Stopping server. Please fix the following error:
2015-09-29 12:07:00: ERROR[main]: Lua: Node name is not set or is not a string!

In thread 7f87b8c7c740:
/home/telesight/minetest/src/server.cpp:511: void Server::step(float): A fatal error occurred: Lua: Node name is not set or is not a string!
Debug stacks:
DEBUG STACK FOR THREAD 7f879ebfd700:
#0  virtual void* EmergeThread::Thread()
(Leftover data: #1  MapBlock* ServerMap::loadBlock(v3s16))
(Leftover data: #2  void ServerMap::loadBlock(std::string*, v3s16, MapSector*, bool))
DEBUG STACK FOR THREAD 7f879f5fe700:
#0  virtual void* EmergeThread::Thread()
(Leftover data: #1  MapBlock* ServerMap::loadBlock(v3s16))
(Leftover data: #2  void ServerMap::loadBlock(std::string*, v3s16, MapSector*, bool))
DEBUG STACK FOR THREAD 7f879ffff700:
#0  virtual void* EmergeThread::Thread()
(Leftover data: #1  MapBlock* ServerMap::loadBlock(v3s16))
(Leftover data: #2  void ServerMap::loadBlock(std::string*, v3s16, MapSector*, bool))
DEBUG STACK FOR THREAD 7f87a8be9700:
#0  virtual void* EmergeThread::Thread()
(Leftover data: #1  MapBlock* ServerMap::loadBlock(v3s16))
(Leftover data: #2  void ServerMap::loadBlock(std::string*, v3s16, MapSector*, bool))
DEBUG STACK FOR THREAD 7f87a95ea700:
#0  virtual void* ServerThread::Thread()
#1  void Server::Receive()
(Leftover data: #2  void Server::SendBlocks(float))
(Leftover data: #3  void Server::SendBlockNoLock(irr::u16, MapBlock*, irr::u8, irr::u16))
(Leftover data: #4  MapBlock* ServerMap::loadBlock(v3s16))
(Leftover data: #5  void ServerMap::loadBlock(std::string*, v3s16, MapSector*, bool))
DEBUG STACK FOR THREAD 7f87b8c7c740:
#0  int main(int, char**)
#1  Dedicated server branch
#2  void dedicated_server_loop(Server&, bool&)
#3  void Server::step(float)