Win10 updates KB 3213986, KB 3210721 have multimonitor problems

On Tuesday, Microsoft released its usual second-Tuesday round of patches for Windows 10. Win10 Anniversary Update, version 1607, KB 3213986 brings the build to 14393.693. Win10 Fall (now “November”) Update, version 1511, KB 3210721 brings the build to 10586.753. Win10 RTM (now “1507”) KB 3210720 brings the build to 10240.17236.

Reading between the lines, there was only one minor security fix: the KB 3214288/MS17-001 patch for Edge that cures an elevation of privilege problem when viewing a web page. Peanuts –the Security Bulletin system goes away next month, so starting in February, it will likely be much more difficult to nail down security components of Win10 cumulative updates.

All three cumulative updates have this acknowledged “known issue”:

Users may experience delayed or clipped screens while running 3D rendering apps (such as games) on systems with more than one monitor.

The official workaround is to disable the second monitor. The unofficial workaround is to simply avoid the patch.

In addition, the 1607 patch has this known issue:

The Cluster Service may not start automatically on the first reboot after applying the update.

The “Workaround is to either start the Cluster Service with the Start-ClusterNode PowerShell cmdlet or to reboot the node.”

The Reddit thread for this patch has been uncharacteristically quiet, with the usual complaints about the update stalling midstream. Microsoft Support Engineer /u/einarmsft has a new diagnosis:

I have found a probable root cause where the symptom you describe fits the preliminary results of the log files from other affected users: an incomplete/corrupted class registered with an ATL server from a previous Cumulative Update which has caused a domino-like effect with subsequent Cumulative Updates

If you’re having trouble getting the 1607 cumulative update installed, please head over to Reddit and add your log files to the collection.

Gatanui on Reddit points out it’s strange for Microsoft to release cumulative updates with known problems. Frequent poster oftheterra offers a plausible explanation:

Although they don’t explain in much detail what behavior the 3D rendering issue describes, I think I know what they are talking about. If that is the case, then it is a problem that has likely been getting tracked for a while, but only presented as a known issue in these notes.

I highly doubt they would both introduce a (potentially) major issue, and be tracking it at the same time. Typically when something big comes up they’ll release an out-of-cycle cumulative update in response. That means they probably don’t have a clear-cut solution the an issue some users are experiencing.

I remain impressed by the quantity and quality of support Microsoft is providing on Reddit for Win10 updates.