After updating I couldn't get The Witcher 3 to run.
Now I've reinstalled it but it won't load my saves.
Ask and ye shall receive.I'm still waiting for something to come along on the slow ring before I upgrade but it's been a long wait.
Last time I ran 10130 I used the Nvidia Windows 10 driver 352.84 and gaming was awful. It may have been down to the driver and replacing it may have helped but I didn't keep the build installed long enough to find out. I'll try a later build but for me at least Windows 10 isn't yet ready to run day to day. (my old system was fine but that's because the drivers were mature).
After updating I couldn't get The Witcher 3 to run.
Now I've reinstalled it but it won't load my saves.
Same here. I had to reinstall to Microsoft Visual C++ Redistributable Packages for Visual Studio 2012 Update 4.
Steam has cloud back up. Did you get the GOG version?