Why can't a Chinese odyssey 2 cheat sheet be verified?

That has nothing to do with expiration. Expiration only reduces the safety factor and will not affect the login game. I think there may be two reasons:

1, GM's mistake, this kind of mistake is similar to the situation that GM couldn't get on some time ago, so you'd better ask friends who play big words if they can get on the secret card.

2, if you can get on, then your number may have been stolen! Now the hacker technology is more developed, even the secret can be stolen!

So if you still can't get on after a while, I suggest you change your card! If you can lose it, you'd better report it quickly!