If you are using a custom tileset, and you are editing levels for your server, make a folder, put the levels in it, copy the tileset.png and put it in there. Open a level, and put the:
NPC Code:
addtiledef yourtilesethere.png, #L, 1;
in a level...
If that doesn't work, PM Wandaman
BTW, I honestly don't know what the index value does. I know 0 and 1 you need to set, and I believe anything 2 and above ignore the code and just use picso1.png