Fix Windows Phone 7/8 + Gmail “Attention Required” Error – WP8
If you’re getting this problem,it’s Google’s Fault, and not the Windows 7 / Windows 8 Phone’s.
Go to the following URL, put your password in and enter the captcha. This will solve the problem and let you use your Gmail account on your Windows Phone.
It seems to disable some captcha security setting on your Gmail Account. Use at your own risk, I don’t know what else it does.