Getting Authentication Error On both sites

Hi @zshan691

Me and Ramóna checked the login with the Facebook button ( the one that currently appears below the “Login” button and above the “Privacy Policy” link ) on the /wp-login.php of the linked page, and it worked fine for both of us.

Could you check please if you can reproduce this problem with other Facebook accounts, too? (I would suggest testing with a Facebook account that was not registered on your site, yet.)

If the problem doesn’t occur with new accounts, then is it possible that earlier you configured Nextend Social Login with the credentials of another Facebook App, and recently you replaced it with a new one?

Hi @zshan691

In this case the problem will be caused by that. Since Facebook uses App scoped user IDs, which means the same user have different user ID in each App. ( E.g. in App1 your Facebook accounts ID is XXXXXXXX but in App2 it is YYYYYYYY.)
When you link a social media account to a WordPress account, we use WordPress user ID and the social media user ID to create a link between the accounts. So, since the new App returns a completely different user ID, the login won’t be possible, as the social media user ids won’t match anymore.

So on a live site, you should never replace the Facebook App.

What I would suggest is:
1.) If there are much more users who registered with the old Facebook App, then you should configure Nextend Social Login with the credentials of your old App. ( Of course in this case those users who registered with the new app will receive the error. )
2.) The users who experience the problem, should login to their WordPress account using the traditional username / password login. Then they should unlink their currently linked Facebook from their WordPress account, and link the Facebook account again over the currently configured Facebook App.

Note: Logged in users can find the Unlink/Link buttons on the /wp-admin/profile.php page by default, but you can also render them with the Nextend Social Login Widget, if you have Unlink and Link enabled:

• https://nextendweb.com/nextend-social-login-docs/nextend-social-login-widget/

or with a shortcode that uses the link and unlink parameters:
[nextend_social_login login="1" link="1" unlink="1"]

Hi @zshan691

I am glad that fixed the problem.

As for your question:
I am sorry, only the users can unlink the social media account from their WordPress accounts.
But if you really want to “unlink” all the Facebook accounts, then you should go to your phpMyAdmin, open our <wp_preffix>social_users table and you could delete the the records manually, where the type is fb.
E.g. this SQL command would delete all the links between the WordPress and Facebook accounts:
DELETE FROMwp_social_usersWHEREtype= 'fb';

But please note that, this will unlink ALL WordPress accounts of your site from the Facebook accounts.

Note:
In “wp_social_users” the “wp_” part needs to be replaced with the preffix of your own database table.