AS : Syndicate worked fine before the previous Redstone update, the trainers for Shadows of Mordor& Ryse both stopped working after this update to build 14316. This has been the only change to my system.
SmartScreen has no effect on the trainers - they had already been "unblocked" when downloaded. I save them to a NAS drive, which has the effect of negating this anyway, and even if I save them to my main drive, this is the first thing I do along with ticking the "run as administrator" box in the file properties.
I have never had any issues with defender blocking any of the trainers. As I said, the only change is updating to a Redstone build. Reading in the AS : Syndicate thread, other people are having similar issues.
(ps turning win def off has no effect)
It's likely that the new build has something that prevents unknown software from accessing or modifying the games.