I am having the same issue on Windows 10 Build 1803. The system seems to detect that the customization event started, but it does not proceed. In my case, I am creating several Linked Clones from the Master VM. In average, if I create 10 Win10 linked clones then at least 3 will have this issue.
From the Event log I can see that the customization starts, but I don't see that it continues:
Started customization of VM PNC2547-29. Customization log located at C:/Temp/vmware-imc/guestcust.log in the guest OS.
Any help on this will be greatly appreciated!