Tapping on Account Sync gives a list of Google apps when they had been last synced. For immediate assistance, contact Google Live Support.
- Change date & time of your device and check if this works. Even if date and time of your device are correct, then also go through following procedure:
- Open Settings App of the android device.
- In the Settings app, you need to tap on System.
- Under the option System, click on Date & Time.
- Scroll through and turn off the options Automatic Time Zone and Automatic date & time.
- Change date and time so that it shows that both are wrong.
- Once you have set wrong date and time, go to home screen.
- Again, go to Settings app, and correct wrong date and time.
- Turn on the options Automatic date & time.
- Again, turn on the option Automatic Time Zone.
If above troubleshooting method does not help, then, contact Google Live Support to make your account work again.
Visit: Google Account Recovery