VM Will Not Clone.
I ran into an interesting issue where a Windows 10 VM wouldn't clone. This was a fresh installation of Windows 10 based from an ISO customized with MSMG, which is by far one of the best methods when removing the junk from Windows 10, especially the unwanted apps. Make sure to document your removals and additions for sanity sake, otherwise you'll end up in a continuous loop of a "did I remember to remove..." thought.
I figured the image was messed up due to the customization of MSMG, but I have no hard facts to prove that. I noticed that sysprep would fail and the rest of the process would halt. After deep investigation into the sysprep error logs and checking the registry, I found a key named "SysprepCorruption" set to 1. This is of course not what I wanted to see. After setting the key to 0 and reapply the customization, the image was able to successfully clone. This applied to both VMware vSphere and vCloud Director.
Set the following key if your VM is failing to clone:
If you continue to run into the cloning issue, please reach out. I've experienced the same issue that was due to the random security applied to Remote Desktop Services, but it's a different resolution and appeared to be fixed in later versions of Windows 10. I'd be more than happy to dig that information up.