I am assuming UUID are generated the same way in Workstation as they are in ESX/ESXi based on the machine name and the directory where the VM's files are stored. That is why you have the conflict - it looks like workstation recognized the issue and generated a new UUID - I would power off the VM and power it back on and see if your still get the initial error.
The link you provided actually references VI Infrastructure so it might not apply wo Workstation.
I have also moved your question to the Workstation forum.
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