The cause depends on what the script was attempting to do, but it could be a firewall blocking, corruption on the computer being accessed, or lack of permissions. Is the script attempting to access a resource on the local computer? Or is it attempting to access a resource remotely on another computer?
Who is running the script? If the resource is remote, is the local computer joined to a domain? Finally, why run the script on a server? Can it be run from a client?