If you create the accounts manually using their email, and then users have to login using Facebook, I don't see any problem. Or does Facebook allow the same email on two accounts? I don't think it is possible.

To António Vilela
l think you have a point there and l think thats my best bet. l will definitely work towards that direction. the facebook and gmail login. Ang again, thank you very much for dedicating you time to help me get the solution. Thank you António.

To António Vilela
l would like to thank you for taking your time, all the efforts you made to point me to the right direction. As you have suggested. l have decided to use the OAuth 2 authentication which works like a charm! for those who are interested here is the link: https://docs.moodle.org/36/en/OAuth_2_authentication and here is my login page to my moodle LMS (having incorporated facebook and Google login) https://asifunde.co.za/asifunde/login/index.php

To Brian Nyathi
You are welcome. Happy to know you found a solution!

Hello Is this applicable for SSO authentication esp.. SAML?

To arturo guinto
The plug-in will not work because SAML send the user out of moodle to login.

Hi, I don't see an option to install it directly on my 3.7 installation
Is it not compatible with 3.7?

when i use unique id plugin shows unable to access- invalid login...please help

@Alejandro Novoa The plugin has been successfully tested in version 3.6 and 3.7.
@Vijaya Kumar Do not set Unique Login as a user authentication method. Please see the correct use in https://docs.moodle.org/20/en/Uniquelogin_authentication

Thank you for your quick response it's working

Hi Antonio, this plugin working in Moodle 3.8.3?....Thanks regards

@JJ Prade The plugin has been successfully tested in version 3.8.

Hi.
It works fine. I recommend to anybody who uses this plugin that, follow the installation instructions. Moving the plug-in to the top position is very important. Otherwise, it may not work with some of the 2-factors verification plugins.
Thank you, Antonio.
Regards.

Hi.
When will version 3.9 be out? Any idea? Does version 3.8 work ok with 3.9
Thanks and Merry Xmas.

I've read the description above and several comments, and I am confused.
If a user is already logged in, and tries to login again (on a different browser or device), what happens exactly? Will the second session be refused or will the first session be closed?
I suggest that this is made clearer in the description, if possible.
Thanks.