Plugin LdapSearch failed. Missing ldap extension

PHP Warning

Warning: "preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead"

Warning: "preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead:"

Warning: "preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead"

Warning: "preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead"

Warning: "preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead"

Warning: "preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead"

Warning: "preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead"

Warning: "preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead"

Warning: "preg_replace(): The /e modifier is deprecated, use preg_replace_callback instead:"