exchange 2013 /preparead fails

setup /prepareschema ran fine

but setup /preparead gives me the following error:

            New-ManagementRoleAssignment -Role "TeamMailboxLifecycleApplication"
 -User $appAccount.Identity -DomainController $RoleDomainController;
            New-ManagementRoleAssignment -Role "MailboxSearchApplication" -User
$appAccount.Identity -DomainController $RoleDomainController;

            Set-PartnerApplication -Identity $exchApp.Identity -LinkedAccount $appAccount.Identity -DomainController $RoleDomainController;;
          }
        " was run: "Couldn't find a user with the identity "mydomain.com/Users/Exchange Online-ApplicationAccount".".

Anand_N