Here is a list of fixes and bugs in Windows 10 build 10576

Besides the earlier mentioned improvements, Windows 10 build 10576 includes a number of fixes and known issues which can cause trouble during everyday use. Read the list below.

Here's the full list of fixes and issues Microsoft has made in this latest build.

In Windows 10 build 10576, the following fixes are available (to quote Microsoft directly):

• We fixed the issue where the Xbox app for Windows 10 would consume gigabytes of memory on your PC if you have any Win32 games (non -Windows Store games) installed on your PC that have been identified as games or added by you in the Xbox app.
• We introduced an early preview of nested virtualization so that people could run Hyper-V Containers in Hyper-V virtual machines with Build 10565. This build includes performance improvements.
• We've been addressing a lot of feedback around localization text UI in various languages and you'll see a lot of that work in this build.
• The search box should now work in this build if you are in a locale where Cortana is not available.

Here is a list of known issues: (again quoting Microsoft directly)

• To continue receiving missed call notifications and send texts from Cortana, you will need to be on this build and higher. We've made a change that improves this experience that requires newer builds.
• When notifications pop up from Action Center, any audio playing (like music from Groove, or videos from the Movies & TV app) gets reduced by 75% for a period of time.
• After upgrading to this build, all your Skype messages and contacts are gone in the Messaging app. The workaround for this is to navigate to C:\Users\\AppData\Local\Packages\Microsoft.Messaging_8wekyb3d8bbwe\LocalCache in File Explorer and either delete or rename the "PrivateTransportId" file. Then restart the Messaging app. Additionally, you can install the app from the Store as an updated app.
• Small form-factor devices, like the Dell Venue 8 Pro, that boot with rotation or virtual mode screen size set larger than the physical screen size will experience a bluescreen on upgrade and will roll back to the previous build.
• After upgrading to this build, the power button on your Surface Pro 3 may no longer put your Surface Pro 3 to sleep and instead shut down.
• WebM and VP9 have been temporarily removed from builds. We continue to develop a VP9 implementation that we intend to ship in Windows. Expect VP9 to return soon in a future build.

That's it.