Leecher

that means map->npc_market_data_db is empty
So check if you have following lines in map.c: Line 3659 (if its without any source edits)
else if(strcmpi(w1,"npc_market_data_db")==0) strcpy(map->npc_market_data_db, w2); and in inter-server.conf: Line 130 or around that
 
npc_market_data_db: npc_market_data  if not, that means you have not updated it properly, so maybe update it via git(which is the most preferred way) or get a new revision
 

This is so much for the update going on. While rAthena is fixing bugs right straight up ahead