Technical issues with Heroes III.

Here's the issue: sometimes in online games (using Hamachi), some players can't select a faction or a hero (by default, it's set to Castle (Humans), and the Hero field displays nothing). They can only choose a resource, gold, or an artifact. However, everything works fine for me, but some other players experience this problem. Why does this happen?

By the way, if someone else creates the game, not me, this problem disappears, but only for some of the affected players. What kind of weirdness is this???