My situation is similar to yours. It could have been opened, but one day the internet speed was too slow, so I refreshed it, and then this happened, and the signature was invalid. What network is busy, too many people enter, it is nonsense, not the reason at all. Just change the computer. It's been days, and it's no use. I can only play on different computers. Once I uninstalled QQ, and then I reinstalled QQ. I could have entered it, but the display was not completely refreshed. As a result, my signature was invalid and useless. I don't know how to solve it.