Fatal Error at login

Hello dear supporters, I got a error at login with the plesk tool. When I hit the login button a new window opens with “about:blank” and the text: Anmeldeinformationen des WordPress-Administrators werden abgerufen. Bitte warten… but nothing happens. The site is working just fine. I just can’t login. And as side note: I am a total rookie!!!

Fatal error: Uncaught Error: Call to undefined function auxin_is_post_type_allowed() in /home/httpd/vhosts/l3coa.ch/httpdocs/wp-content/plugins/auxin-pro-tools/includes/general-hooks.php:63 Stack trace: #0 /home/httpd/vhosts/l3coa.ch/httpdocs/wp-includes/class-wp-hook.php(307): auxpro_add_post_types_metafields(”) #1 /home/httpd/vhosts/l3coa.ch/httpdocs/wp-includes/class-wp-hook.php(331): WP_Hook->apply_filters(NULL, Array) #2 /home/httpd/vhosts/l3coa.ch/httpdocs/wp-includes/plugin.php(474): WP_Hook->do_action(Array) #3 /home/httpd/vhosts/l3coa.ch/httpdocs/wp-settings.php(587): do_action(‘init’) #4 /usr/local/psa/admin/plib/modules/wp-toolkit/vendor/wp-cli/vendor/wp-cli/wp-cli/php/WP_CLI/Runner.php(1291): require(‘/home/httpd/vho…’) #5 /usr/local/psa/admin/plib/modules/wp-toolkit/vendor/wp-cli/vendor/wp-cli/wp-cli/php/WP_CLI/Runner.php(1212): WP_CLI\Runner->load_wordpress() #6 /usr/local/psa/admin/plib/modules/wp-toolkit/vendor/wp-cli/vendor/wp-cli/wp-cli/php/WP_CLI/Bootstrap/LaunchRunner.php(23): WP_CLI\Runner->start() #7 /usr/local/psa/admin/plib/modules/wp-toolkit/vendor/wp-cli/vendor/wp-cli/wp-cli/php/bootstrap.php(77): WP_CLI\Bootstrap\LaunchRunner->process(Object(WP_CLI\Bootstrap\BootstrapState)) #8 /usr/local/psa/admin/plib/modules/wp-toolkit/vendor/wp-cli/vendor/wp-cli/wp-cli/php/wp-cli.php(27): WP_CLI\bootstrap() #9 /usr/local/psa/admin/plib/modules/wp-toolkit/vendor/wp-cli/vendor/wp-cli/wp-cli/php/boot-fs.php(17): require_once(‘/usr/local/psa/…’) #10 /usr/local/psa/admin/plib/modules/wp-toolkit/vendor/wp-cli/wpt-wp-cli.php(31): require_once(‘/usr/local/psa/…’) #11 {main} thrown in /home/httpd/vhosts/l3coa.ch/httpdocs/wp-content/plugins/auxin-pro-tools/includes/general-hooks.php on line 63 Error: Es gab einen kritischen Fehler auf deiner Website.Erfahre mehr über die Problembehandlung in WordPress. Es gab einen kritischen Fehler auf deiner Website.

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