installation - Windows 8 upgrade to windows 8.1 RTM fails with error code 0x101 - 0x2000C

I have a MSDN Subscription and downloaded Windows 8.1 RTM today.

It fails to install.

After mounting the ISO and installing (with a Windows 8.1 Pro product code), selecting "Keep my apps and settings", it copies all installation files, restarts and then bluescreens at around 50%, then rolls back to the previous version.

System has 64 GB Memory, Supermicro, Xeon E5-1650, Intel SSD, runs Hyper-V, Windows 8 Pro.

What may be causing this and how do I fix it?