yith social login for woocomerce is not working for facebook login

hi,
the other socials work well?
what’s the matter with facebook? Can you describe the issue?
Have you enabled the error log?

In the file wp-config.php of your installation replace
define(‘WP_DEBUG’, false );
with:
define(‘WP_DEBUG’, true);
define(‘WP_DEBUG_DISPLAY’, false);
define(‘WP_DEBUG_LOG’, true);

Then do a login with facebook, and check the file debug.log inside the folder wp-content/

Let me know!

in debug.log iam getting error
[18-May-2017 11:36:03] PHP Notice: force_ssl_login is deprecated since version 4.4! Use force_ssl_admin() instead. in /var/www/vhosts/webworldindia.com/httpdocs/bigmuscles/wp-includes/functions.php on line 3618

I haven’t found any solutions to this problem, is it possible to fix or how do we proceed? Kind of Urgent

[19-Dec-2017 16:36:47 UTC] PHP Fatal error:  Uncaught Error: Call to a member function authenticate() on null in ...../public_html/wp-content/plugins/yith-woocommerce-social-login-premium/includes/class-yith-social-login.php:180
Stack trace:
#0 ...../public_html/wp-includes/class-wp-hook.php(286): YITH_WC_Social_Login->get_login_request('')
#1 ...../public_html/wp-includes/class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array)
#2 ...../public_html/wp-includes/plugin.php(453): WP_Hook->do_action(Array)
#3 ...../public_html/wp-settings.php(450): do_action('init')
#4 ...../public_html/wp-config.php(112): require_once('/...')
#5 ...../public_html/wp-load.php(37): require_once('/...')
#6 ...../public_html/wp-login.php(12): require('/...')
#7 {main}
  thrown in ...../public_html/wp-content/plugins/yith-woocommerce-social-login-premium/includes/class-yith-social-login.php on line 180