I forgot to tell that I don't know if I need to decrypt game. I want to open RPG Maker MV game and just try to open .rpgproject file in game folder, like I did in RPG Maker VX Ace case. But I got an error "Failed to load: data/actors.json". There was same error with RPG Maker VX Ace, and that was because game was encrypted. Maybe I don't understand something.
There are two different things that one might need to do with RPGM MV games: unpack, or decrypt. To unpack, you need to use Enigma VB Unpacker, and make sure you use the latest version to avoid errors, found here:
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. Also if the game is large, you will need free space on the drive of about at least 10x the size of the game. So if the game is 2GB, you need at least 20GB free space on the drive. IDK why, that's just how it works.
Once it's unpacked, make sure the game.exe is in the correct directory, you might have a folder where the unpacked content is in and you need to move all that content up one directory level into the game.exe folder. Also there may be an extra .exe file, you can go ahead and delete the one not named Game.exe as well as the original unpacked file (make sure you have a backup). Sometimes, once the content is unpacked, asset files might also be encrypted using Enterbrain's proprietary formats. Then you would need to use one of the RPG MV Decrypter programs available. There are two prominent ones I think, I'll link the one I use more often:
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. To use that, navigate to the Game.exe directory after you've ensured that the game can start properly, and it will decrypt all the asset files.