domain mapping failover after setup sunrise

Hi. I have a website, and I want to create some websites each one with your on domain. I´ve setup WPMU with subdomains. and I´ve installed some plugins from WPMUDEV. When I tried to setup domain mapping, that plugin said to copy sunrise file to certain folder and write define( 'SUNRISE', 'on' ); on wp-config.php
after that my main website turn off
Could you help-me ?