A bug in the Active Directory Rights Management Server (AD RMS) Add Roles wizard in Windows Server 2008 can cause a blank error message to appear when you attempt validate the SQL server. The message was intended to notify you that the account you are logged in with does not belong to the sysadmin group on the SQL server.
This problem occurs only when you are adding the AD RMS server role on a computer running Windows Server 2008. It does not occur on Windows Server 2008 R2.
To fix the problem, cancel the Add Roles, add the account you are using to add the AD RMS server role to the sysadmin group of the SQL server, and then restart the Add Roles wizard to add the AD RMS server role.
For more information about preparing to install AD RMS, see Pre-installation Information for Active Directory Rights Management Services.