Huge update: 753 Mb patch. The contents (not all) can be seen here:https://support.microsoft.com/en-us/help/12387/windows-10-update-history
and the files affected here: https://support.microsoft.com/en-us/kb/3194496
It doesn't fix the issue where drives randomly disappear from Windows or the SSD freezing issues that some users are experiencing.
Problems: Some people are reporting that the update appears to be stuck at 45% or 94%. Not really: Just slowed to a snail's pace. Choice: Wait ot download manually instead. Only it isn't in the catalog nor in the download center. Yet.
Some users are saying it it fails to install and that they get the "undoing" screen, the log shows 0x800F0922.
There's nothing to do yet if you get a failure to install...but, "they're working on it".
Update: Microsoft has issued a fix for Windows 10 users caught in the KB3194496 installation loop:
http://www.eweek.com/enterprise-apps/microsoft-fixes-windows-10-update-install-loop-bug.html
Source:
http://www.ghacks.net/2016/09/30/cumulative-windows-10-update-kb3194496-installation-issues/?_m=3n%2e0038%2e1920%2ehj0ao01hy5%2e1zyu