1.there is a network problem which has being maintained. you can come later or tomorrow.
2.it is unstable for logging on Yahoo now, please try later
3.you just need to press the "ENTER" key
4.maybe you need to chek your E-mail's capacity or the filling-in format.
照直翻譯的哈，不過壹般來說網絡都是說連接CONNECTION出現問題，維修用升級UPGRADE代替，而且不說登陸不穩定，也是說連接不穩定，供參考吧。。