Procedure to change the main address that ActiveCollab runs on is as follows:
Open config/config.php file under ActiveCollab’s directory, and change ROOT_URL value,
Clear cache by clearing everything from /cache directory, except .htaccess file. If you are using memory caching (with memcached), flush the cache to clear it,
Clear the content of /compiled directory, except .htaccess file,
Open ActiveCollab in your browser using the new address to confirm that everything’s working correctly.
Use this procedure only when the same servre can serve both old and new address. If that is not the case, please follow the procedure to move ActiveCollab to the new server.