Hi everyone!
I have issue ((
I have finished the first two scenarious of armageddon blade and... game doesnt open third scenatrio for me. It just switch on first scenario, but I have finished in early. So there is some bug I suppose. I use heroes 3 HD+ and nothing else.

I would really appreciate your help!

That is a trap by design many of us have tripped over.
If you start a new scenario in the campaign you must do it from a save file with the previous won scenarios. Otherwise the game will not know that you have beaten earlier scenarios.

When you finish a campaign, do not exit to the main menu. Start the next campaign immediately, then save and exit.

Or, if you do exit, then the next time you start, load the save file that was created as Mondaklb wrote. Don't start a New Game.

What you can do now is use the cheat "nwcredpill" for immediate victory to replay the first campaign.

http://www.heroesofmightandmagic.com/heroes3sod/cheatcodes.shtml