There are several reasons why you might experience log in issues:
1) If your classroom internet connection is weak or has a problem.
2) If your device is not running the latest version of Handouts and iOS/Android.
3) If your school has not whitelisted the following domains:
4) If you registered on iOS, you won't be able to access your account on an Android tablet, and vice versa. The iOS and Android systems are not compatible at the moment, but we are working on having this functionality ready as soon as possible.
If none of these seems to be the problem please get in touch at email@example.com, letting us know your account details and what system you registered on (iOS/Android). We will look into the problem as soon as possible.