If you were using RVSiteBuilder to create/maintain your site, you'll need to wait until it's been re-installed into cPanel. There are a lot of loose ends from the migration being tied up right now, and setting up the site builder is one of them. (Many account holders are equally- or worse-affected by other issues, so while the site builder might be your number one priority, it may come in at a somewhat lower number in the big picture view.)