Few days ago I saw this strange error message when I try to login my Google account on the HTC Desire (my previous phone):
Can’t establish a reliable data connection to the server
Since I cannot login to google, I cannot use the Play Store, Gmail, Youtube etc. My phone was connected to the home WiFi and the internet is definitely working.
I was thinking maybe this phone is already old and maybe Google changed something in their Authentication API. When I was about to give up after trying for about 10 times, I realize something: my Date and time was not probably set! It was reset to 1980 Jan 1. (Because I took out the battery)
Setting the correct System date and time, the phone works like a charm.
It turns out authentication requires establishing a secure connection with Google’s server. The SSL certificate contains a expiration date which would be compared against the system date of the Android system. If the system date is too far in the past or in the future, the validation would be failed, thus the connection cannot be established. This is a security measures of the HTTPS connection, so check your system date next time encountering such strange error message.