I've been trying to get this update to install since November or so.
I've done almost everything suggested on this and other sites. I've run the troubleshooter tool, I've downloaded and attempted to install from a clean boot, I've run the sfc and dsim solutions. I've deleted the SoftwareDistribution folder and let it recreate itself. A couple of updates installed, but NOT this one.
Is 1709 really essential to getting any of the other security updates? As near as I can tell, it's just some 3D paint program and a few other bells and whistles. If it really is essential, then why are so many people having trouble getting it installed?