Unable to get google button to work

Peter,
You need to type that URL into the Authorized URI Redirects box. The image in the 2nd post (with the error message) has the exact URL you need to enter there.

The URL will not be automatically filled out. Google generates one, but it doesn't work for our purposes, so you'll need to update it with the URL shown in the video or the one from that error page you linked too.

I hope that explains, but if not, let me know.

Thanks,
Alex

Peter,
If you have the "Automatically Link Users by Email :" and the user is logging in with Facebook or Google and that social network email is the same to an existing user in Joomla, the accounts will automatically be linked. If there is no matching email, then it depends on your registration mode.
* If set to "Regular Registration", the user will be brought to the Login / Register page where they can login with their existing account.
* If set to "Automatic Registration", a new user account will be created for the user. In this case, there's no way for JFBConnect to know that they user already has an account.

The SCLogin module also has a setting for "Show Connect Account Button(s)". That will show the FB or G+ login button when user's are logged in *if* they haven't connected to those accounts. That will allow the user to 'connect' their Joomla account to those social networks and login with them later.

I hope that helps explain,
Alex