Alongside all of the new features tagging along in Windows 10 and Windows 10 Mobile build 14291 for Windows Insiders, there are also a number of bug fixes and known issues tagging along. Since the build is being pushed out to both PC and Mobile, there are separate lists of issues and fixes for both platforms. Here's the full skinny on what's fixed and what's still broken:

What's Fixed for PC

This issue causing the notification area ("systray") to look out of alignment when turning on the "always show all icons in the notification area" should now be fixed.

We fixed the issue where connectivity to older Wi-Fi networks using the WEP encryption security method may be broken.

We fixed an issue where the "X" to close the "Find of Page" toolbar in Microsoft Edge is displayed off screen on 8-inch devices when in portrait mode.

We fixed an issue where the USB icon in the notification area was reverting to the old icon when ejecting drives.

We fixed an issue where clicking the suggested search in Microsoft Edge resulted in a URL to the search as the search string.

What's Fixed for Mobile

We fixed the issue where connectivity to older Wi-Fi networks using the WEP encryption security method may be broken.

We fixed an issue resulting in slower text input speed the more words were typed.

We have improved Word Flow recognition of longer words.

The All apps list has been updated to now follow the "Make Text Larger" ease of access setting.

We fixed an issue where Settings would sometimes list unresolved app names under Extras.

We fixed an issue where touch targets could be out of alignment in the Photos picker.

Known Issues for PC

We continue to investigate 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.

Your PC may freeze when plugging in an Xbox One or Xbox 360 controller and other gamepads in this build.

If you use Hyper-V and have a Virtual Switch configured for your network adapter, you may see an error indicator (red-colored "X") for your network adapter in the notification area of your taskbar. The error indicator is incorrect and your network adapter should continue to work just fine.

We are seeing reports of some apps such as QQ crashing. We are currently investigating, and this bug may also impact older apps such as Windows Live Mail and Expression Encoder 4.

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.

Known Issues for Mobile