[WanDaMan]

Add

NPC Code:

---

removetiledefs; 

---

above the script.

Also, instead of #L add the level name including the format. Example:

wandaman_level.nw

When in offline mode check that the level is in the same directory as the tileset.

Edit:
Try this, you're using addtiledef2

NPC Code:

---

//#CLIENTSIDE

if (created){

  removetiledefs;

  addtiledef anzell_tiles.png,#L,0;

}

---