I had this same issue after upgrading from 7.10 to 7.13, however the fix posted here didn't work for me. Putting the files in C:\Windows\Temp or C:\Windows\Temp\Vmware still failed when trying to publish the pool. Extending the clone-prep timeout value did not work either.

After engaging VMware support, it was discovered that placing the postsync files in a directory off of the root (for example C:\Scripts) fixed the issue for me.

Just an FYI for everyone.