Question about the map "Empire of the World".

Stormbringer, and how can this be done?

You can view it using HeroesInfo, and you can fix it, for example, with this program - http://vitonic.narod.ru/heroes3se.html.
Or, better yet, ask baratorch to fix this bug in the next version of the HD Mod - the reason is known, and a save file with the bug exists.