Can't upgrade to Windows 10 in Parallels 10

I have followed the instructions to upgrade my Windows 7 VM in Parallels 10 to Windows 10 but am having no success.
Using the Media Creation Tool, the Windows 10 download seems to proceed properly. The next step, "Verifying your download" completes properly.
But at about the 75% mark in "Creating Windows 10 Media" i suddenly get the message:

"Something happened"
0x80070070-0xC19001DF

Any help will be greatly appreciated.
John

 

You may not have allocated enough memory or virtual disk space. See https://forum.parallels.com/threads...ng-win-10-under-parallels.329225/#post-774352