Sign up with Google is not permitted.

we are trying to resurrect the use of social logins on a web site. www.cabe.ca Twitter and Facebook work fine but Google+ does not seem to function. The account links correctly. However, after logging out, it is not possible to login with the google account. The error message is shown in the subject. I created a fresh google app following your instructions. The settings are shown in the attached png file.

It maybe trying to create a new account for whatever reason. Edit the user and ensure the Google ID field isn't empty. Under the Registration tab set "Register" to "Yes" for Google and see what it tells you then. Does Twitter and Facebook work fine?

Twitter and Facebook work fine. I cleared the Google id field several times. It would sync the account and put an id field in but when I logged out, the login would not work. I also tried a completely different account with similar problems.

Within CB Connect > Parameters > Google > Registration set "Register" to "Yes" and under Link set "Linking" to "Yes" then retry and see if any further errors output and if so what do they say. It's either trying to register the user twice or that parameter is blocking the linking from logging in for some reason. If it's trying to register twice it maybe some odd issue with it being unable to find a user with the matching Google ID.

I did all of that with an used account. It did the link but when I tried to login, I got this message
Message
The email 'pmj@jacobsonconsulting.ca' is already in use. Please login to link your account.

Seams to be working perfectly fine in my tests. Enable debug mode and maximum error reporting in Joomla global configuration. Next in CB Connect > Parameters > Google > Application set "Debug" to "Enable". Now try logging in and you should see debug output for all of the HTTP calls to Google. If everything was successful the first "Response Body" should contain an access_token. The second "Response Body" should be the JSON response with your Google profile data and that ID in it should match that of your users Google ID field.

Please be 110% sure CB and CB Connect are up to date. I've seen 1 too many posts in the past week of issues caused purely due to being out of date. If you've CB Auto Actions installed and its acting on registration, login, or update triggers then unpublish it during your tests to see if your auto actions maybe doing it. Do not map the core fields (username, name, etc..) under the Registration tab either (this includes Google ID).