Error 77 message is caused by the username/password being rejected for some reason.
You can only get this error message if you are running a version of LabQuest less than 2.7. It can be caused by using the wrong username/password, but it is most likely being rejected for using an older type of encryption. The best solution is to update your LabQuest to version 2.7 or higher:
After you update, you will need to redo the email setup.
If you don't update, and you created your Google account after Fall 2015, your account has stricter security settings by default that won't allow the old version of the LabQuest software to send e-mail. You can try to change the setting:
1. Log into the Gmail account from a computer
2. Go to:
3. Choose "Turn on".
If you get a message indicating this is not permitted, advise your IT department.
Note it may take a few minutes for the change to propagate though Gmail's servers.
The other reasons why Gmail might reject the sign in are here:
We recommend creating an account that is only used by your LabQuest devices. If the only device using this e-mail address is your LabQuest 2, there isn't a loss of security by using the "less secure" setting.
TIL 2736: What do the error codes from the LabQuest 2 Email Configuration Test mean?