Errors(or better to say WARNINGS) like "monstername can not be found", means that you do not have the monster in your monsters dir, or iits not linked in monsters.xml. if you dont have this creature dont worry, server will still work.
When you see "cannot create item on x y z" open map editor, and just delte all items on this tile, add items manually after that on this position.
"Map is loaded, nothing happens" black screen means not that nothing happend. go to map->towns->thais copy the coordinates of thais, then "jump to position" and get to the map.