Last week the KB3189866 update was released and my computer tried to install it. Just before the reboot it proceeded to 35% and it initiated a reboot. The update was continued and quickly went to 65-70%. From that point it was very slow. It took about 1-2 hours to reach the 97%. At that time, the computer rebooted and the update was rolled back (also took an hour).
I have already read some issues with this update and that you should install the offline updater. It has the same problem. Microsoft released KB3193494 to resolve the download issue, so I tried again. Still the same problem :-(
The event log shows the following messages:
21-09-16 21:09:45 - A reboot is necessary before package KB3193494 can be changed to the Installed state.
21-09-16 22:18:56 - Package KB3193494 failed to be changed to the Installed state. Status: 0x800f0923.
Status 0x800f0922 and 0x800f0816 have been shown as well for when the package failed to change to the Installed state.
My Dell Precision 5510 (Intel Xeon E3-1505M v5, 32GB RAM, 1TB NVMe SSD, nVidia Quadro M1000M) is running Windows 10 (anniversary update). All drivers have been updated to the latest versions.
Update September 29, 2016: Cumulative update KB3194496 still has the same issue :-(