Microsoft has provided a list of what issues have been fixed and what is broken in the just released Windows 10 PC preview build 14279 for members of the Insiders Fast ring.

Here are the issues that have been fixed, according to Microsoft's Windows Insider head Gabriel Aul:

  • We fixed an issue where Microsoft Edge and Cortana were crashing for users with roaming profiles.
  • We fixed an issue where Cortana would continue to show reminders that have been completed.
  • We fixed an issue where items copied/moved to the desktop would not display until the desktop is manually refreshed by right-clicking on the desktop and choosing "Refresh" or pressing F5.
  • We fixed an issue where downloading certain drivers from Windows Update was causing some PCs to bluescreen.

There are also some known issues with this build, according to Aul:

  • We're investigating an issue in which some Surface Pro 3, Surface Pro 4, and Surface Book devices experience a freeze or hang and all input such as keyboard/trackpad and touch do not work. The workaround is to hold down the power button to force the device to hard-reboot.
  • We are continuing to track several issues reported by Insiders where some PCs will freeze or bluescreen when resuming from hibernation. Disabling hibernation is a workaround in some cases until this is fixed.
  • If you have Kaspersky Anti-Virus, Internet Security, or the Kaspersky Total Security Suite installed on your PC there is a known driver bug that prevents these programs from working as expected in builds from the Development Branch. We are partnering with Kaspersky to fix this issue for a future release, but at this time there are no known workarounds. While this issue is present, we recommend using Windows Defender or another third party anti-virus product of your choice to remain protected.
  • Turning on the "always show all icons in the notification area" setting disrupts the layout of the notification area ("systray"). Your notification area will look out of alignment.
  • We are seeing reports of crashes with apps such as QQ crashing due to an OS reliability issue we are currently investigating. This bug is also impacting older apps such as Windows Live Mail and Expression Encoder 4.

Source: Microsoft