There are a number of areas you may want to double-check. First off, double-check that there is contact information listed in Home > User > Conference Site Management > Scheduled Conference Setup > 1.3, Principal Contact Information.
Then check that you have the proper contact information listed in Home > User > Conference Site Management > Website Management > 1.2, Principal Contact for Conference Website.
Finally, if you are using the registration system, also make sure that you have filled out the appropriate registration contact information at Home > User > Conference Site Management > Registration > Registration Policies.
You should enter, at minimum, the name and email for these contacts.
Please let me know if you run into further trouble.