According to the official KB page, this cumulative update pushes OS version to 14393.693, and just like expected, it doesn’t bring any new features, but only performance improvements and bug fixes.
First and foremost, the update improves reliability of some apps, including Groove Music, which should now offer smoother playback in the background. Additionally, App-V video playback and the Remote Desktop performance has also been refined.
Other apps and OS features, including Microsoft Edge, Internet Explorer, Windows Update, PCI bus drivers, the Windows Kernel, and input devices are also getting improvements with this cumulative update.
There are several important bug fixes included in Windows 10 cumulative update KB3213986, such as a patch for an issue causing a device with fingerprint authentication to fail to turn the screen back on when the authentication is performed with the display off.
Microsoft says that the very same update also fixes a problem with license conversion of Server Core from evaluation to retail version, as well as a bug preventing users from opening Internet shortcut (.URL) files with Internet Explorer when Enhanced Protected Mode is enabled.
The software giant has also posted two know issue with the update, one of which is causing the Cluster Service to not start automatically on first reboot after applying the patch. The workaround is to reboot the computer again, to start the Cluster Service with the Start-ClusterNode PowerShell cmdlet or to reboot the node.
A second known bug causes delayed or clipped screens while running 3D rendering apps (such as games) on systems with more than one monitor, and Microsoft says that launching the app in window mode (not full screen) or with just one monitor connector could fix it.
Until now, there are no reports of failed installs, and the cumulative update seems to be working fine on our testing machine, but we’ll keep an eye out on reports and will let you know should any problems be experienced. Source: softpedia