there isn't a console window
Console window == terminal. Your screenshot shows that you're launching it from console.
And it's very strange there's no output at all.
my game is fairly big and there are a lot of "doubtful places".
Then you just must use
print(). Normally, you should use debugging and testing from the start. Just begin from something.
And by the way, what exactly do you mean by "release builds"?
Also, I'd suggest to export another project (like demos), and see how it behaves with console output.