Yeah the post I linked shows how to fix it if you're using C#, tbh I'm not sure what would be the easiest way to fix this or if it's possible to do in the world editor.
Assuming you can't simply fix it in the world editor, you're going to need to use an mpq editor to extract the war3map.w3i file, then edit it somehow, and then import the updated war3map.w3i back into your map. I could edit the file for you if you send me the extracted war3map.w3i.