I have gone through all the steps to upgrade my standalone Plesk-Billing v5.6 to v6.0 bundled and it just doesn't work. I only upgraded to the New 9.0 to have the integration....I sure am glad that I made plenty of backups so I could get my old system back up and running. I've tried filling out tickets with the errors, have also contacted licensing support to get a v6.0 key, and haven't gotten any responses. Looks like Parallells has bitten off more than it could chew when they tried to take everybody else's product and make it their own. ANd I am not usually one to gripe about Sw-.... oops... Parallels.