Error on login

Hi, I have a problem, I have logged in as admin, so I can change settings, but anyone else can’t login to site even I as admin from other browser, I have this error in wfConfig.php.

Fatal error: Call to a member function bind_param() on boolean in /websites/123reg/LinuxPackage22/wa/tc/ht/watchthehype.com/public_html/wp-content/plugins/wordfence/lib/wfConfig.php

When I disable plugin by renaming directory, when user try to login it always redirects to login page. And I try to install Wordfence Assistant, but it can’t be activated, it says “1 plugin ativated”, but it’s not activated.