zubeldialuis on "[Plugin: WordPress MU Domain Mapping] is it working on 4.0?"

i try to instal but when i active plugin i get this error

Fatal error: Cannot redeclare dm_text_domain() (previously declared in /var/www/vhosts/****************.com/httpdocs/wp-content/mu-plugins/domain_mapping.php:29) in /var/www/vhosts/*****************.com/httpdocs/wp-content/plugins/wordpress-mu-domain-mapping/domain_mapping.php on line 30

thanks

https://wordpress.org/plugins/wordpress-mu-domain-mapping/