Dual-factor authentication isn't a WordPress thing, it's a Google+ thing.
See Advanced Sign-in Security
If you have this "2 step verification" enabled in your google account wpgplus will fail.
Have you looked at what is in the debug file in your wpgplus directory?
The plugin tries to log you in to GPlus itself, via Curl, so it shouldn't matter if you are logged in to GPlus in your browser or not
Oh, No I don't have any "2 step verification" in my G+ , Just my G+ has 1 step to login!
in here : site.com/wp-admin/options-general.php?page=WPGPlus.php
I put my gmail email and password... I downloaded and installed this plugin form wordpress.org all of files is correct and complete but this plugin don't work ! I don't see where table in DB ? all of my DB tables is :
wp_BWPS_d404 wp_BWPS_ll wp_BWPS_lockouts wp_commentmeta wp_comments wp_contact_form_7 wp_links wp_options wp_postmeta wp_posts wp_redirection_groups wp_redirection_items wp_redirection_logs wp_redirection_modules wp_smileys wp_terms wp_termsmeta wp_term_relationships wp_term_taxonomy wp_usermeta wp_users wp_wps_bans wp_wps_logins wp_wps_logs
where data of this plugin come to save?
help me please