Current questions and answers regarding the map editor.

Please help. I'm having a problem creating duel heroes. I open Tools/Create Duel Preset in the map editor, create my hero, and save it. The map editor sees it, but when I try to open it, I get an error message. The game doesn't recognize the created hero; in online play, it simply doesn't exist. I have a licensed copy of the game, and I don't have any problems playing online. Can someone please HELP?