We want to start by apologising for this error.
We fixed the Nothing Install Problem.
We have released this game and got the information about this problem from players.
So we have investigated this problem, but at first we thought this problem arise from the steam error. Because we could play the game, and the people around us could also play it.
But the error reports didn't stop. We checked the developer page (SteamWorks) carefully, looking at the release setting tab, and Finally we found the "Included deposit" was empty. This means that people who received the DLKey can play, but the player who bought this game cannot play.
We have set the deposit in release package.
Now you can download and play the game.
The error was due to the lack of knowledge about release procedure in steam.
We will make every effort to ensure this error won’t happen again by reading carefully steamworks documents.
We hope that you accept our deepest apologies.