Probably your Gmail Account may have been locked after repeated incorrect logins. I would suggest you to unlock your Gmail login by using this link - https://www.google.com/accounts/UnlockCaptcha? Then try using correct username and password for your pattern lock. If you can sign into the account on the phone after you do this, then this will unlock the device. If this does not work, or is not an option, you will need to have your device reset. A hard reset will set the phone back to the default settings, erasing everything besides the content stored on the SD card.
Turn power off.
With the phone turned off, press and hold Volume Down button on left panel of phone, then press Power lock button.
When phone’s display turns on, release Volume Down button.
Then press Power button. You will get an option to "are you sure you to continue with erase-Press Power Key to confirm
All data will be deleted from phone, excluding microSD card.
6. Phone will clear storage and reboot to Setup screen
Hope this helps
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