Did you try invoking the Power shell script outside the vco as normal powershell script?
>> "You are not currently connected to any servers. Please connect first using a Connect cmdlet"
This error points out that Connect-VI server call has failed by some reason. What comes to my mind is if you have some special charackters in the username/password/host that might get encoded.
That's why I suggest :
1. First testing the script outside the vCO
2. If it works try to invoke it as external script from vCO providing the same parameters. But first modify the script to print the provided parameteres (username/password/hostname) from the script itself to make sure that the correct values are provided to PowerShell script.