I ran the tool and it concluded I was missing the C++ redist. I installed it, got green across the board, but saving still crashed me to the desktop.
In the end I changed my group policy to restore my Documents folder to its original location (C:\users\...)
After a reboot (and a long wait for the system to copy all of my stuff back to the SSD) I was able to play the game and save.
Let's hope they get this sorted eventually, I don't like having my documents on my system drive.
