I have some kind of bug with patch 3.1. I installed it, I launch the game, and it says that I have version 3.0. I tried to reinstall it, but it says that the patch is already installed.
After thinking for a bit, I remembered the problem with the map editor - it helped.
In short, the essence of the error is that there were Russian characters in the path... if you have the same, try to uninstall Heroes (otherwise the patch will not install, if you tried) and reinstall it in an English-language folder, and then install the patch on top.
Added after 38 minutes
I haven't had time to play properly yet, but I was glad that such a small flaw as an incomplete translation has been fixed, because the English names of the Dwarf heroes and the Altar of the Order were annoying (or is it just me?).
A funny story happened after I installed the patch...
I launched a save game, and I have a glitch in map view mode - the bottom panels are raised about 3 cm higher - it was really annoying... I already thought - why did I install the patch... but everything was fine when I created a new game =))