I don't understand what is the issue you faced with. I suggest you try to run %DD_HOME%\iCDB\win32\bin\iCDBRSCMConfigurator.exe, to check RSCM is installed or correctly configued. If not, you may take a look on this post http://communities.mentor.com/message/31371#31371
Based on the error message I'd say the problem is that the credentials used to start the RSCM service (assuming it is running) do not allow the process spawned by the service (iCDBNetServer) access to the design data. This is usually the case when the service is using the default system credentials to run and the data is on a remote file system.
I'd check the credentials used to run the RSCM service. You can read about that here:
If you don't have access the SupportNet, open your Infohub and go to the Remote Server Configuration Manager and Server Manager Administrator's Guide. There is a section in there entitled 'Setting up the RSCM Server as a Windows Service', which explains how to configure the service credentials.
If you are not familiar with the RSCM service, you should read the entire section called 'RSCM Server Administration'.
Mentor Graphics Customer Support