I deleted all the maps in the folder, leaving only this one – the result is the same.
It launched once through the multiplayer option, but subsequent restarts kick me back to the faction selection page.
There's an option to reinstall the game, but I don't see the point in doing that for just one map. Because the other maps launch and play without any major issues.
UPDATE. I tried launching the map using enemy heroes and teams (Vlad/Garuna). It worked. But I don't see the point in playing as them for obvious reasons.
It seems there's some kind of problem with the player's hero.