All Domains Missing After Plesk Parallels Upgrade From 11 To 12

I've just used the Parallels upgrade service (autoinstaller in terminal). I upgraded from Parallels 11 to 12. I logged into the panel, it asked me all the personal info and I started to get nervous. Now that I am properly logged in, all my 165 customers and domains are missing!?! I've checked on the server, and the data is still present in the /var/www/vhosts directories, although nothing shows up in Parallels. I've also looked through the Parallels docs/forums/help but I can't find any starting points, apart from this very helpful suggestion to restore the server from backup: http://kb.sp.parallels.com/en/11190 Is there any way I can roll back to eleven? And, is there any chance I can get my domains/customers/sites/dignity back?