Make sure your NLM is running and installed as a service. Ensure that your AutoCAD licenses are available. If your server looks good and you can PING it from the client, receiving a valid IPv4 address (IPv6 won't work - i.e. WIndows 7 or Server 2008) then the problem may be on the client with the CascadeInfo.cas file.
For more detailed information about the CascadeInfo.cas file, please refer to the Autodesk Support Knowledge Base article found here:
Log into access your profile, ask and answer questions, share ideas and more. Haven't signed up yet? Register