Unable to create custom B2C application

Hi

I am trying to create a custom B2C application via NWDS .

The track is ready , all the SCAs including the CUSTCRMPRJ are available in NWDS

But as I say right click and say Create New DC in CUSTCRMPRJ , the name dropdown shows blank.

If you click finish it says "Invalid name :appropriate prefix not found;choose another name or name server.