How to fix Invalid configuration for device '0' when cloning a virtual machine
In case you are stuck with this error, here is what I found.
Problem -While trying to clone a virtual machine from a template or a VM (ESX 4.1), I get an "Invalid configuration for device '0' " error after the cloning was about 80% complete.
Only items I changed for the VM (Edit Virtual Hardware option) were the MAC address for the NIC from Automatic to Manual and the ISO device type to "Client Device".
What I did was to clone the virtual machine with the default settings and then make the required changes after it completes.
Hope this helps someone!