Uncaught Error: Class “…\…\RequestParameters\RequestParameters”

Uncaught Error: Class “Cleantalk\ApbctWP\RequestParameters\RequestParameters” not found in /var/www/example .com/htdocs/wp-content/plugins/cleantalk-spam-protect/cleantalk.php:2819
Stack trace: 0 /var/www/example .com/htdocs/wp-includes/class-wp-hook.php(324): apbct_store__urls() 1 /var/www/example .com/htdocs/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters() 2 /var/www/example .com/htdocs/wp-includes/plugin.php(517): WP_Hook->do_action() 3 /var/www/example .com/htdocs/wp-includes/template-loader.php(13): do_action() 4 /var/www/example .com/htdocs/wp-blog-header.php(19): require_once(‘…’) 5 /var/www/example .com/htdocs/index.php(17): require(‘…’) 6 {main}

thrown in /var/www/example .com/htdocs/wp-content/plugins/cleantalk-spam-protect/cleantalk.php on line 2819